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Office of Scientific and Technical Information
Study of the decay asymmetry parameter and CP violation parameter in the Lambdac+ --> Lambda pi+ decay
E-Print Network (OSTI)
Using data from the FOCUS (E831) experiment at Fermilab, we present a new measurement of the weak decay-asymmetry parameter alpha(Lambdac) in Lambdac --> Lambda pi decay. Comparing particle with antiparticle decays, we obtain the first measurement of the CP violation parameter : A = [alpha(Lambdac)+alpha(antiLambda_c)]/[alpha(Lambdac)-alpha(antiLambda_c)]. We obtain alpha(Lambdac)=-0.78+-0.16+-0.13 and A = -0.07+-0.19+-0.12 where errors are statistical and systematic.
J. M. Link
Uncertainty evaluation of delayed neutron decay parameters
In a nuclear reactor, delayed neutrons play a critical role in sustaining a controllable chain reaction. Delayed neutron�s relative yields and decay constants are very important for modeling reactivity control and have been studied for decades. Researchers have tried different experimental and numerical methods to assess these delayed neutron parameters. The reported parameter values vary widely, much more than the small statistical errors reported with these parameters. Interestingly, the reported parameters fit their individual measurement data well in spite of these differences. This dissertation focuses on evaluation of the errors and methods of delayed neutron relative yields and decay constants for thermal fission of U-235. Various numerical methods used to extract the delayed neutron parameter from the measured data, including Matrix Inverse, Levenberg-Marquardt, and Quasi-Newton methods, were studied extensively using simulated delayed neutron data. This simulated data was Poisson distributed around Keepin�s theoretical data. The extraction methods produced totally different results for the same data set, and some of the above numerical methods could not even find solutions for some data sets. Further investigation found that ill-conditioned matrices in the objective function were the reason for the inconsistent results. To find a reasonable solution with small variation, a regularization parameter was introduced using a numerical method called Ridge Regression. The results from the Ridge Regression method, in terms of goodness of fit to the data, were good and often better than the other methods. Due to the introduction of a regularization number in the algorithm, the fitted result contains a small additional bias, but this method can guarantee convergence no matter how large the coefficient matrix condition number. Both saturation and pulse modes were simulated to focus on different groups. Some of the factors that affect the solution stability were investigated including initial count rate, sample flight time, initial guess values. Finally, because comparing reported delayed neutron parameters among different experiments is useless to determine if their data actually differs, methods are proposed that can be used to compare the delayed neutron data sets.
Wang, Jinkai
B Decay
NLE Websites -- All DOE Office Websites (Extended Search)
Decay Decay B mesons are short-lived and decay inside the beam pipe, which is about 2.5 cm (1 inch) in diameter. Physicists project the tracks seen in the detector elements outside the beampipe back to where the particles must have traveled inside the beam pipe. We call a point where particles collide or decay a vertex. A way to identify a B meson is to look for two vertices with a gap between them. On the left is a standard event picture. On the right is a blowup of what happens close to the collision point inside the beam pipe. The vertex is where the B meson along with other particles was created and the secondary vertex is where it decayed. The solid green lines are the actual tracks of the decay particles outside the beam pipe. The dotted lines are the projection of the tracks into the beam pipe. Where they intersect are the vertices. The B travels between the first vertex and the secondary vertex along the black dotted line before it decays. Thus, the gap between the two vertices is a measure of the lifetime of the B meson. We will be looking for this decay length in our data. We will find a minimum or "threshold" value that will tell us to save events for further analysis.
Glossary Term - Alpha Decay
Universe Previous Term (10 Most Abundant Elements in the Universe) Glossary Main Index Next Term (Alpha Particle) Alpha Particle Alpha Decay Alpha Decay Diagram Alpha decay is one...
Measurement of the Alpha Asymmetry Parameter for the Omega- to Lambda K- Decay
We have measured the alpha parameter of the Omega- to Lambda K- decay using data collected with the HyperCP spectrometer during the 1997 fixed-target run at Fermilab. Analyzing a sample of 0.96 million Omega- to Lambda K^-, Lambda to p pi- decays, we obtain alpha_Omega*alpha_Lambda = [1.33+/-0.33(stat)+/-0.52(syst)] x 10^{-2}. With the accepted value of alpha_Lambda, alpha_Omega is found to be [2.07+/-0.51(stat)+/-0.81(syst)] x 10^{-2}.
HyperCP Collaboration; Y. C. Chen; R. A. Burnstein; A. Chakravorty; A. Chan; W. S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; G. Gidal; P. Gu; H. R. Gustafson; C. Ho; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; D. M. Kaplan; L. M. Lederman; N. Leros; M. J. Longo; F. Lopez; L. C. Lu; W. Luebke; K. B. Luk; K. S. Nelson; H. K. Park; J. P. Perroud; D. Rajaram; H. A. Rubin; P. K. Teng; J. Volk; C. G. White; S. L. White; P. Zyla
Semileptonic Decays
SciTech Connect
The following is an overview of the measurements of the CKM matrix elements |V{sub cb}| and |V{sub ub}| that are based on detailed studies of semileptonic B decays by the BABAR and Belle Collaborations and major advances in QCD calculations. In addition, a new and improved measurement of the ratios R(D{sup (*)}) = {Beta}({bar B} {yields} D{sup (*)}{tau}{sup -}{bar {nu}}{sub {tau}})/{Beta}({bar B} {yields} D{sup (*)}{ell}{sup -}{bar {nu}}{sub {ell}}) is presented. Here D{sup (*)} refers to a D or a D* meson and {ell} is either e or {mu}. The results, R(D) = 0.440 {+-} 0.058 {+-} 0.042 and R(D*) = 0.332 {+-} 0.024 {+-} 0.018, exceed the Standard Model expectations by 2.0{sigma} and 2.7{sigma}, respectively. Taken together, they disagree with these expectations at the 3.4{sigma} level. The excess of events cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model.
Luth, Vera G.; /SLAC
Measurement of the CP Violation Parameters in B0 -> pi+ pi- Decays
We present a measurement of the time-dependent charge-parity (CP) violation parameters in B0 -> pi+ pi- decays. The results are obtained from the final data sample containing 772 million BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. We obtain the CP violation parameters Acp = +0.33 +/- 0.06 (stat) +/- 0.03 (syst) and Scp = -0.64 +/- 0.08 (stat) +/- 0.03 (syst), where Acp and Scp represent the direct and mixing-induced CP asymmetry, respectively. Using an isospin analysis including results from other Belle measurements, we find 23.8 < phi2 < 66.8 degrees is disfavored at the 1 sigma level, where phi2 is one of the three interior angles of the CKM unitarity triangle related to B_{u,d} decays.
Belle Collaboration; J. Dalseno; K. Prothmann; C. Kiesling; I. Adachi; H. Aihara; K. Arinstein; D. M. Asner; V. Aulchenko; T. Aushev; A. M. Bakich; A. Bala; A. Bay; P. Behera; V. Bhardwaj; B. Bhuyan; A. Bondar; G. Bonvicini; A. Bozek; M. Bra?ko; T. E. Browder; V. Chekelian; A. Chen; P. Chen; B. G. Cheon; K. Chilikin; R. Chistov; K. Cho; V. Chobanova; S. -K. Choi; Y. Choi; D. Cinabro; M. Danilov; Z. Dole�al; Z. Dr�sal; A. Drutskoy; D. Dutta; K. Dutta; S. Eidelman; H. Farhat; J. E. Fast; M. Feindt; T. Ferber; A. Frey; V. Gaur; S. Ganguly; R. Gillard; Y. M. Goh; B. Golob; J. Haba; T. Hara; K. Hayasaka; H. Hayashii; T. Higuchi; Y. Hoshi; W. -S. Hou; H. J. Hyun; T. Iijima; A. Ishikawa; R. Itoh; Y. Iwasaki; T. Julius; D. H. Kah; E. Kato; H. Kawai; T. Kawasaki; D. Y. Kim; H. J. Kim; J. B. Kim; J. H. Kim; K. T. Kim; Y. J. Kim; K. Kinoshita; J. Klucar; B. R. Ko; P. Kody�; S. Korpar; P. Kri�an; P. Krokovny; B. Kronenbitter; A. Kuzmin; Y. -J. Kwon; S. -H. Lee; J. Li; Y. Li; L. Li Gioi; J. Libby; C. Liu; D. Liventsev; P. Lukin; D. Matvienko; K. Miyabayashi; H. Miyata; R. Mizuk; G. B. Mohanty; A. Moll; T. Mori; H. -G. Moser; N. Muramatsu; R. Mussa; Y. Nagasaka; M. Nakao; M. Nayak; E. Nedelkovska; C. Ng; C. Niebuhr; N. K. Nisar; S. Nishida; O. Nitoh; S. Ogawa; S. Okuno; S. L. Olsen; P. Pakhlov; G. Pakhlova; C. W. Park; H. Park; H. K. Park; T. K. Pedlar; R. Pestotnik; M. Petri?; L. E. Piilonen; M. Ritter; M. R�hrken; A. Rostomyan; S. Ryu; H. Sahoo; T. Saito; Y. Sakai; S. Sandilya; L. Santelj; T. Sanuki; V. Savinov; O. Schneider; G. Schnell; C. Schwanda; A. J. Schwartz; D. Semmler; K. Senyo; O. Seon; M. E. Sevior; M. Shapkin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; Y. -S. Sohn; E. Solovieva; S. Stani?; M. Stari?; M. Steder; M. Sumihama; K. Sumisawa; T. Sumiyoshi; U. Tamponi; G. Tatishvili; Y. Teramoto; K. Trabelsi; T. Tsuboyama; M. Uchida; S. Uehara; T. Uglov; Y. Unno; S. Uno; P. Urquijo; Y. Ushiroda; S. E. Vahsen; C. Van Hulse; P. Vanhoefer; G. Varner; V. Vorobyev; M. N. Wagner; C. H. Wang; P. Wang; X. L. Wang; M. Watanabe; Y. Watanabe; K. M. Williams; E. Won; B. D. Yabsley; H. Yamamoto; Y. Yamashita; S. Yashchenko; Y. Yook; C. Z. Yuan; Y. Yusa; Z. P. Zhang; V. Zhilich; V. Zhulanov; A. Zupanc
Measurement of the neutrino-spin correlation parameter B neutron decay using ultracold neutrons
Science Conference Proceedings (OSTI)
We present a new approach to measuring the neutrino-spin correlation parameter B in neutron decay. The approach combines the technology of large-area ion-implanted silicon detectors being developed for the abBA experiment, with an ultracold neutron source to provide more precise neutron polarimetry. The technique detects both proton and electron from the neutron decay in coincidence. B is determined from an electron-energy-dependent measurement of the proton spin asymmetry. This approach will provide a statistical precision of 1 x 10-4 . The systematic precision is still being evaluated, but is expected to be below 1 x 10-3 , and could approach 1 x 10-4 . A measurement of B with this precision would place constraints on supersymmetric extensions to the Standard Model.
Wilburn, Wesley S [Los Alamos National Laboratory
Suppressed Charmed B Decay
This thesis describes the measurement of the branching fractions of the suppressed charmed B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays and the non-resonant B{sup 0} {yields} D{sup (*)-} {eta}{pi}{sup +} decays in approximately 230 million {Upsilon}(4S) {yields} B{bar B} events. The data have been collected with the BABAR detector at the PEP-II B factory at the Stanford Linear Accelerator Center in California. Theoretical predictions of the branching fraction of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decays show large QCD model dependent uncertainties. Non-factorizing terms, in the naive factorization model, that can be calculated by QCD factorizing models have a large impact on the branching fraction of these decay modes. The predictions of the branching fractions are of the order of 10{sup -6}. The measurement of the branching fraction gives more insight into the theoretical models. In general a better understanding of QCD models will be necessary to conduct weak interaction physics at the next level. The presence of CP violation in electroweak interactions allows the differentiation between matter and antimatter in the laws of physics. In the Standard Model, CP violation is incorporated in the CKM matrix that describes the weak interaction between quarks. Relations amongst the CKM matrix elements are used to present the two relevant parameters as the apex of a triangle (Unitarity Triangle) in a complex plane. The over-constraining of the CKM triangle by experimental measurements is an important test of the Standard Model. At this moment no stringent direct measurements of the CKM angle {gamma}, one of the interior angles of the Unitarity Triangle, are available. The measurement of the angle {gamma} can be performed using the decays of neutral B mesons. The B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay is sensitive to the angle {gamma} and, in comparison to the current decays that are being employed, could significantly enhance the measurement of this angle. However, the low expected branching fraction for the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay channels could severely impact the measurement. A prerequisite of the measurement of the CKM angle is the observation of the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay on which this thesis reports. The BABAR experiment consists of the BABAR detector and the PEP-II e{sup +}e{sup -} collider. The design of the experiment has been optimized for the study of CP violation in the decays of neutral B mesons but is also highly suitable for the search for rare B decays such as the B{sup 0} {yields} D{sup (*)-} a{sub 0}{sup +} decay. The PEP-II collider operates at the {Upsilon}(4S) resonance and is a clean source of B{bar B} meson pairs.
Snoek, Hella Leonie; /Vrije U., Amsterdam
H Decay
Suspects . . . er Candidates Suspects . . . er Candidates Two huge physics task forces, CDF and DZero, are after the Higgs at Fermilab. They will be looking for events with b quarks and Ws as candidate Higgs events. More about candidate events. To learn more about Higgs, check out: Politics, Solid State and the Higgs by David Miller, and the cartoon version. Also good reading: The Search for Higgs in Beamline, March 2001. You and your classmates will join the particle hunt by doing a sweep for evidence through CDF data to learn how to identify bs and Ws. You will be looking for minimum or "threshold" values for certain parameters. Also, you will learn something about the data analysis that must be done after the candidate events are identified to determine the value of the mass. Be sure to keep notes on all your work.
Glossary Term - Beta Decay
Avogadro's Number Avogadro's Number Previous Term (Avogadro's Number) Glossary Main Index Next Term (Beta Particle) Beta Particle Beta Decay Beta decay results in the emission of an electron and antineutrino, or a positron and neutrino. Beta decay is one process that unstable atoms can use to become more stable. There are two types of beta decay, beta-minus and beta-plus. During beta-minus decay, a neutron in an atom's nucleus turns into a proton, an electron and an antineutrino. The electron and antineutrino fly away from the nucleus, which now has one more proton than it started with. Since an atom gains a proton during beta-minus decay, it changes from one element to another. For example, after undergoing beta-minus decay, an atom of carbon (with 6 protons) becomes an atom of nitrogen (with 7 protons).
Handbook on string decay
We explain simple semi-classical rules to estimate the lifetime of any given highly-excited quantum state of the string spectrum in flat spacetime. We discuss both the decays by splitting into two massive states and by massless emission. As an application, we study a solution describing a rotating and pulsating ellipse which becomes folded at an instant of time -- the ``squashing ellipse''. This string interpolates between the folded string with maximum angular momentum and the pulsating circular string. We explicitly compute the quantum decay rate for the corresponding quantum state, and verify the basic rules that we propose. Finally, we give a more general (4-parameter) family of closed string solutions representing rotating and pulsating elliptical strings.
Roberto Iengo; Jorge G. Russo
B Decay Length
Threshold Decay Length Threshold Decay Length Data from 292 B events are in an Excel spreadsheet that looks like this table. To find the threshold decay length: Sort the data by descending decay lengths, dt. Run Event No. B Mass GeV/c2 ptB GeV/c dt cm Velocity v/c Lab Lifetime sec Rest Lifetime sec Bin 65160 642324 5.277 7.966 0.388 66500 89978 5.274 20.508 0.940 Get the data. Make a histogram of decay lengths. Rather than graphing all the lengths as individual points, physicists group the data. They consider the range of the data and divide it into "bins" of equal size. A histogram is a graph of the number of events in each bin vs. the bin range. We are looking for the smallest decay length that fits the exponential curve. This will indicate the length of the decay as detemined by that experimental run.
Overview of rare K decays
The status and future prospects of searches for and studies of forbidden and highly suppressed K decays are reviewed. Here the author discusses three areas of recent activity in rare K decay. These are lepton-flavor violating decays, which are entirely forbidden in the Standard Model, K{sub S} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0}, which is of interest from the point of view of CP-violation, and `one loop` decays of the form K{sup 0,{+-}} {yields} ({pi}{sup 0,{+-}})l{bar l}, that can throw light on Standard Model CP-violation and determine parameters such as V{sub td}.
Littenberg, L.
The search for proton decay
Following a very brief description of the theoretical developments which motivated the search for proton decay
R. Bionta; G. Blewitt; C. B. Bratton; D. Casper; B. G. Cortez; G. W. Foster; W. Gajewski; K. S. Ganezer; M. Goldhaber; T. J. Haines; T. W. Jones; D. Kielczewka; W. R. Kropp; J. G. Learned; E. Lehmann; J. M. LoSecco; H. S. Park; J. Shultz; S. Seidel; H. W. Sobel; J. L. Stone; L. R. Sulak; J. C. van der Velde
Recent developments in radiative B decays
We report on recent theoretical progress in radiative B decays. We focus on a calculation of logarithmically enhanced QED corrections to the branching ratio and forward-backward asymmetry in the inclusive rare decay anti-B --> X(s) l+ l-, and present the results of a detailed phenomenological analysis. We also report on the calculation of NNLO QCD corrections to the inclusive decay anti-B --> X(s) gamma. As far as exclusive modes are concerned we consider transversity amplitudes and the impact of right-handed currents in the exclusive anti-B --> K^* l+ l- decay. Finally, we state results for exclusive B --> V gamma decays, notably the time-dependent CP-asymmetry in the exclusive B --> K^* gamma decay and its potential to serve as a so-called ``null test'' of the Standard Model, and the extraction of CKM and unitarity triangle parameters from B --> (rho,omega) gamma and B --> K^* gamma decays.
Huber, T
Hyperon radiative decay
The radiative decay widths of the low-lying strange baryons are calculated both within the relativistic quark bag model and the nonrelativistic potential model. These widths are found to depend sensitively upon the quark-model dynamics through multiplet mixing and q/sup 4/q-bar admixtures. The comparison between our calculated results and the very limited experimental data is discussed.
Kaxiras, E.; Moniz, E.J.; Soyeur, M.
The Decay of Convective Turbulence
Using simulations with a large-eddy model we have studied the decay of convective turbulence in the atmospheric boundary layer when the upward surface sensible heat flux is suddenly stopped. The decay of turbulent kinetic energy and temperature ...
F. T. M. Nieuwstadt; R. A. Brost
Rare Decays of the $?^{'}$
We have searched for the rare decays of the eta prime meson to e+ e- eta, e+ e- pizero, e+ e- gamma, and e mu in hadronic events at the CLEO II detector. The search is conducted on 4.80 fb^-1 of e+ e- collisions at the Cornell Electron Storage Ring. We find no signal in any of these modes, and set 90% confidence level upper limits on their branching fractions of 2.4 X 10^-3, 1.4 X 10^-3, 0.9 X 10^-3, and 4.7 X 10^-4, respectively. We also investigate the Dalitz plot of the common decay of the eta prime to pi+ pi- eta. We fit the matrix element with the Particle Data Group parameterization and find Re(alpha) = -0.021 +- 0.025, where alpha is a linear function of the kinetic energy of the eta.
R. A. Briere
Radioactive decay data tables
The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals.
Kocher, D.C.
Note on unparticle decays
The coupling of an unparticle operator O{sub U} to standard model particles opens up the possibility of unparticle decays into standard model fields. We study this issue by analyzing the pole structure (and spectral function) of the unparticle propagator, corrected to account for one-loop polarization effects from virtual standard model particles. We find that the propagator of a scalar unparticle (of scaling dimension 1{<=}d{sub U}<2) with a mass gap m{sub g} develops an isolated pole, m{sub p}{sup 2}-im{sub p}{gamma}{sub p}, with m{sub p}{sup 2} < or approx. m{sub g}{sup 2} below the unparticle continuum that extends above m{sub g} (showing that the theory would be unstable without a mass gap). If that pole lies below the threshold for decay into two standard model particles, it corresponds to a stable unparticle state (and its width {gamma}{sub p} is zero). For m{sub p}{sup 2} above the threshold, the width is nonzero and related to the rate of the unparticle decay into standard model particles. This picture is valid for any value of d{sub U} in the considered range.
Delgado, Antonio [Department of Physics, 225 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556-5670 (United States); Espinosa, Jose R. [IFT-UAM/CSIC, Facultad Ciencias UAM, 28049 Madrid (Spain); IFAE, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain) and ICREA, Institucio Catalana de Recerca i Estudis Avancats, Barcelona (Spain); No, Jose Miguel [IFT-UAM/CSIC, Facultad Ciencias UAM, 28049 Madrid (Spain); Quiros, Mariano [IFAE, Universitat Autonoma de Barcelona, 08193 Bellaterra, Barcelona (Spain) and ICREA, Institucio Catalana de Recerca i Estudis Avancats, Barcelona (Spain); Theory Division, CERN, Geneva 23 CH-1211 (Switzerland)
E6 Gamma Decay
Rare electric hexacontatetrapole (E6) transitions are studied in the full (f{sub 7/2},f{sub 5/2},p{sub 3/2},p{sub 1/2}) shell-model basis. Comparison of theory to the results from the gamma decay in {sup 53}Fe and from inelastic electron scattering on {sup 52}Cr provides unique and interesting tests of the valence wavefunctions, the models used for energy density functionals and into the origin of effective charge.
Brown, B. Alex [Department of Physics and Astronomy, and National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824-1321 (United States); Rae, W. D. M. [Knollhouse, Garsington, Oxford, Oxfordshire, OX44 9DB (United Kingdom)
Rare B Decays
Recent results from Belle and BaBar on rare B decays involving flavor-changing neutral currents or purely leptonic final states are presented. Measurements of the CP asymmetries in B {yields} K*{gamma} and b {yields} s{gamma} are reported. Also reported are updated limits on B{sup +} {yields} K{sup +}{nu}{bar {nu}}, B{sup +} {yields} {tau}{sup +}{nu}, B{sup +} {yields} {mu}{sup +}{nu} and the recent measurement of B {yields} X{sub s}{ell}{sup +}{ell}{sup -}.
Jackson, P.D.; /Victoria U.
Search for CP violation in hyperon decays.
Direct CP violation in nonleptonic hyperon decays can be established by comparing the decays of hyperons and anti-hyperons. For {Xi} decay to {Lambda} {pi} followed by {Lambda} to p{pi}, the proton distribution in the rest frame of Lambda is governed by the product of the decay parameters {alpha}{sub {Xi}} {alpha}{sub {Lambda}}. The asymmetry A{sub {Xi}{Lambda}}, proportional to the difference of {alpha}{sub {Xi}}{alpha}{sub {Lambda}} of the hyperon and anti-hyperon decays, vanishes if CP is conserved. We report on an analysis of a fraction of 1997 and 1999 data collected by the Hyper CP (E871) collaboration during the fixed-target runs at Fermilab. The preliminary measurement of the asymmetry is {Alpha}{sub {Xi}{Lambda}} = [-7 {+-} 12(stat) {+-} 6.2(sys)] x 10{sup -4}, an order of magnitude better than the present limit.
Zyla, Piotr; Chan, A.; Chen, Y.C.; Ho, C.; Teng, P.K.; Choong, W.S.; Gidal, G.; Fu, Y.; Gu, P.; Jones, T.D.; Luk, K.B.; Turko, B.; James, C.; Volk, J.; Felix, J.; Burnstein, R.A.; Chakrovorty, A.; Kaplan, D.M.; Lederman, L.M.; Luebke, W.; Rajaram, D.; Rubin, H.A.; Solomey, N.; Torun, Y.; White, C.G.; White, S.L.; Leros, N.; Perroud, J.P.; Gustafson, H.R.; Longo, M.J.; Lopez, F.; Park H.K.; Clark, K.; Jenkins, M.; Dukes, E.C.; Durandet, C.; Holmstrom, T.; Huang, M.; Lu, L.; Nelson, K.S.
Diagnosing oscillatory growth or decay
An analytical study is presented for an oscillatory system in terms of four constants, namely amplitude, phase, growth or decay rate, and frequency. (MOW)
Buneman, O.
B to tau Leptonic and Semileptonic Decays
Decays of B mesons to states involving {tau} leptons can be used as a tool to search for the effects of new physics, such as those involving a charged Higgs boson. The experimental status of the decays B {yields} {tau}{nu} and B {yields} D{sup (*)}{tau}{nu} is discussed, together with limits on new physics effects from current results. Leptonic and semileptonic decays of B mesons into states involving {tau} leptons remain experimentally challenging, but can prove a useful tool for constraining Standard Model parameters, and also offer to constrain the effects of any new physics that may exist including the presence of a charged Higgs boson.
Barrett, M.; /Brunel U.
The Particle Adventure | Particle decays and annihiliations ...
Particle decays and annihiliations - Half life A lump of uranium left to itself will gradually decay, one nucleus at a time. The rate of decay is measured by how long it would take...
virtual particles. Virtual particles do not violate the conservation of energy. The kinetic energy plus mass of the initial decaying particle and the final decay products is...
Beta-decay beyond the standard model
We discuss possible sources of new interactions in beta-decay and the role of beta-decay experiments in obtaining information on them. 46 refs.
Herczeg, P.
The decay of hot nuclei
The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.
Moretto, L.G.; Wozniak, G.J.
CRBRP decay heat removal systems
The Decay Heat Removal Systems for the Clinch River Breeder Reactor Plant (CRBRP) are designed to adequately remove sensible and decay heat from the reactor following normal shutdown, operational occurrences, and postulated accidents on both a short term and a long term basis. The Decay Heat Removal Systems are composed of the Main Heat Transport System, the Main Condenser and Feedwater System, the Steam Generator Auxiliary Heat Removal System (SGAHRS), and the Direct Heat Removal Service (DHRS). The overall design of the CRBRP Decay Heat Removal Systems and the operation under normal and off-normal conditions is examined. The redundancies of the system design, such as the four decay heat removal paths, the emergency diesel power supplies, and the auxiliary feedwater pumps, and the diversities of the design such as forced circulation/natural circulation and AC Power/DC Power are presented. In addition to overall design and system capabilities, the detailed designs for the Protected Air Cooled Condensers (PACC) and the Air Blast Heat Exchangers (ABHX) are presented.
Hottel, R.E.; Louison, R.; Boardman, C.E.; Kiley, M.J.
Selected Aspects of Neutron Decay
Precision measurements of neutron decay offer complementary access to particle physics at small distance scales or high energies. In particular they allow tests of the V-A structure of the weak interaction. Among many experimental activities which are ongoing around the world we present two new experiments which are planned or studied for the near future. While the neutron lifetime still bears significant experimental uncertainties and thus has to be studied with greatest precision the two-body decay ($n\\to H\\bar\
Stephan Paul
CDF results on B decays
The authors present recent CDF results on B lifetimes, B meson mass measurements, ratios of branching ratios, and rare decays. In addition, they present the first measurement of time-dependent B{sub d} mixing at CDF. Several results have been updated and a few new ones included since the workshop.
Skarha, J.E. [Johns Hopkins Univ., Baltimore, MD (United States)
Rare B decays at CDF
The confidence level limits of the CDF search for the B{sub s}{sup 0} and B{sub d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} rare decays and the branching ratio measurement of B{sub s}{sup 0} {yields} D{sub s}{sup +} D{sub s}{sup -} are presented.
Farrington, Sinead M.; /Liverpool U.
Neutron Beta Decay Studies with Nab
Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab spectrometer.
Bae�ler, S; Alonzi, L P; Balascuta, S; Barr�n-Palos, L; Bowman, J D; Bychkov, M A; Byrne, J; Calarco, J R; Chupp, T; Vianciolo, T V; Crawford, C; Frle�, E; Gericke, M T; Gl�ck, F; Greene, G L; Grzywacz, R K; Gudkov, V; Harrison, D; Hersman, F W; Ito, T; Makela, M; Martin, J; McGaughey, P L; McGovern, S; Page, S; Penttil�, S I; Po?ani?, D; Rykaczewski, K P; Salas-Bacci, A; Tompkins, Z; Wagner, D; Wilburn, W S; Young, A R
S. Bae�ler; R. Alarcon; L. P. Alonzi; S. Balascuta; L. Barr�n-Palos; J. D. Bowman; M. A. Bychkov; J. Byrne; J. R. Calarco; T. Chupp; T. V. Vianciolo; C. Crawford; E. Frle�; M. T. Gericke; F. Gl�ck; G. L. Greene; R. K. Grzywacz; V. Gudkov; D. Harrison; F. W. Hersman; T. Ito; M. Makela; J. Martin; P. L. McGaughey; S. McGovern; S. Page; S. I. Penttil�; D. Po?ani?; K. P. Rykaczewski; A. Salas-Bacci; Z. Tompkins; D. Wagner; W. S. Wilburn; A. R. Young
mass in a radioactive decay go? Recall that we said that when uranium decays into thorium and an alpha particle, 0.0046 u of mass appears to have been lost. As Einstein said,...
B, D and K Decays
The present report documents the results of Working Group 2: B, D and K decays, of the workshop on Flavor in the Era of the LHC, held at CERN from November 2005 through March 2007. With the advent of the LHC, we will be able to probe New Physics (NP) up to energy scales almost one order of magnitude larger than it has been possible with present accelerator facilities. While direct detection of new particles will be the main avenue to establish the presence of NP at the LHC, indirect searches will provide precious complementary information, since most probably it will not be possible to measure the full spectrum of new particles and their couplings through direct production. In particular, precision measurements and computations in the realm of flavor physics are expected to play a key role in constraining the unknown parameters of the Lagrangian of any NP model emerging from direct searches at the LHC. The aim of Working Group 2 was twofold: on one hand, to provide a coherent, up-to-date picture of the status of flavor physics before the start of the LHC; on the other hand, to initiate activities on the path towards integrating information on NP from high-p{sub T} and flavor data. This report is organized as follows. In Sec. 1, we give an overview of NP models, focusing on a few examples that have been discussed in some detail during the workshop, with a short description of the available computational tools for flavor observables in NP models. Sec. 2 contains a concise discussion of the main theoretical problem in flavor physics: the evaluation of the relevant hadronic matrix elements for weak decays. Sec. 3 contains a detailed discussion of NP effects in a set of flavor observables that we identified as 'benchmark channels' for NP searches. The experimental prospects for flavor physics at future facilities are discussed in Sec. 4. Finally, Sec. 5 contains some assessments on the work done at the workshop and the prospects for future developments.
Artuso, M.; Asner, D.M.; Ball, P.; Baracchini, E.; Bell, G.; Beneke, M.; Berryhill, J.; Bevan, A.; Bigi, I.I.; Blanke, M.; Bobeth, Ch.; Bona, M.; Borzumati, F.; Browder, T.; Buanes, T.; Buchalla, G.; Buchmuller, O.; Buras, A.J.; Burdin, S.; Cassel, D.G.; Cavanaugh, R.; /Syracuse U. /Carleton U. /Durham U., IPPP /Rome U. /INFN, Rome /Karlsruhe U. /RWTH Aachen U. /Fermilab /Queen Mary, U. of London /Notre Dame U. /Munich, Tech. U. /Munich, Max Planck Inst. /Dortmund U. /Annecy, LAPP /ICTP, Trieste /Taiwan, Natl. Central U. /Hawaii U. /Bergen U. /Munich U. /CERN /Liverpool U.
PyDecay/GraphPhys: A Unified Language and Storage System for Particle Decay Process Descriptions
To ease the tasks of Monte Carlo (MC) simulation and event reconstruction (i.e. inferring particle-decay events from experimental data) for long-term BaBar data preservation and analysis, the following software components have been designed: a language ('GraphPhys') for specifying decay processes, common to both simulation and data analysis, allowing arbitrary parameters on particles, decays, and entire processes; an automated visualization tool to show graphically what decays have been specified; and a searchable database storage mechanism for decay specifications. Unlike HepML, a proposed XML standard for HEP metadata, the specification language is designed not for data interchange between computer systems, but rather for direct manipulation by human beings as well as computers. The components are interoperable: the information parsed from files in the specification language can easily be rendered as an image by the visualization package, and conversion between decay representations was implemented. Several proof-of-concept command-line tools were built based on this framework. Applications include building easier and more efficient interfaces to existing analysis tools for current projects (e.g. BaBar/BESII), providing a framework for analyses in future experimental settings (e.g. LHC/SuperB), and outreach programs that involve giving students access to BaBar data and analysis tools to give them a hands-on feel for scientific analysis.
Dunietz, Jesse N.; /MIT /SLAC
Rare Decays of the $\\eta^{'}$
Briere, R A; Ford, W T; Gritsan, A; Krieg, H; Roy, J D; Smith, J G; Alexander, J P; Baker, R; Bebek, C; Berger, B E; Berkelman, K; Blanc, F; Boisvert, V; Cassel, David G; Dickson, M; Von Dombrowski, S; Drell, P S; Ecklund, K M; Ehrlich, R; Foland, A D; Gaidarev, P B; Galik, R S; Gibbons, L K; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Hopman, P I; Jones, C D; Kreinick, D L; Lee, T; Liu, Y; Meyer, T O; Mistry, N B; Ng, C R; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Thayer, J G; Thies, P G; Valant-Spaight, B L; Warburton, A; Avery, P; Lohner, M; Prescott, C; Rubiera, A I; Yelton, J; Zheng, J; Brandenburg, G; Ershov, A; Gao, Y S; Kim, D Y J; Wilson, R; Browder, T E; Li, Y; Rodr�guez, J L; Yamamoto, H; Bergfeld, T; Eisenstein, B I; Ernst, J; Gladding, G E; Gollin, G D; Hans, R M; Johnson, E; Karliner, I; Marsh, M A; Palmer, M; Plager, C; Sedlack, C; Selen, M; Thaler, J J; Williams, J; Edwards, K W; Janicek, R; Patel, P M; Sadoff, A J; Ammar, R; Baringer, P; Bean, A; Besson, D; Coppage, D; Davis, R; Kotov, S A; Kravchenko, I V; Kwak, N; Zhao, X; Anderson, S; Frolov, V V; Kubota, Y; Lee, S J; Mahapatra, R; O'Neill, J J; Poling, R A; Riehle, T; Smith, A; Ahmed, S; Alam, M S; Athar, S B; Jian, L; Ling, L; Mahmood, A H; Saleem, M; Timm, S; Wappler, F; Anastassov, A; Duboscq, J E; Gan, K K; Gwon, C; Hart, T; Honscheid, K; Kagan, H; Kass, R; Lorenc, J; Schwarthoff, H; Spencer, M B; Von T�rne, E; Zoeller, M M; Richichi, S J; Severini, H; Skubic, P L; Undrus, A E; Bishai, M; Chen, S; Fast, J; Hinson, J W; Lee, J; Menon, N; Miller, D H; Shibata, E I; Shipsey, I P J; Kwon, Y; Lyon, A L; Thorndike, E H; Jessop, C P; Lingel, K; Marsiske, H; Perl, Martin Lewis; Savinov, V; Ugolini, D W; Zhou, X; Coan, T E; Fadeev, V; Korolkov, I Ya; Maravin, Y; Narsky, I; Stroynowski, R; Ye, J; Wlodek, T; Artuso, M; Ayad, R; Dambasuren, E; Kopp, S E; Majumder, G; Moneti, G C; Mountain, R; Schuh, S; Skwarnicki, T; Stone, S; Titov, A; Viehhauser, G; Wang, J C; Wolf, A; Wu, J; Csorna, S E; McLean, K W; Marka, S; Xu, Z; Godang, R; Kinoshita, K; Lai, I C; Pomianowski, P A; Schrenk, S; Bonvicini, G; Cinabro, D; Greene, R; Perera, L P; Zhou, G J; Chan, S; Eigen, G; Lipeles, E; Schmidtler, M; Shapiro, A; Sun, W M; Urheim, J; Weinstein, A J; W�rthwein, F; Jaffe, D E; Masek, G E; Paar, H P; Potter, E M; Prell, S; Sharma, V; Asner, D M; Eppich, A; Gronberg, J B; Hill, T S; Lange, D J; Morrison, R J; Nelson, T K; Richman, J D; Roberts, D
Probing Radiative Solar Neutrinos Decays
Motivated by a pilot experiment conducted by F.Vannucci et al. during a solar eclipse, we work out the geometry governing the radiative decays of solar neutrinos. Surprisingly, although a smaller proportion of the photons can be detected, the case of strongly non-degenerate neutrinos brings better limits in terms of the fundamental couplings. We advocate satellite-based experiments to improve the sensitivity.
Fr�re, J M
NIST: Marie Curie and the NBS Radium Standards - Decay ...
... Decay schemes from uranium, actinium and thorium series Decay schemes from uranium, actinium and thorium series as given in Frederick ...
Profile-based adaptation for cache decay
Cache decay is a leakage-reduction mechanism that puts cache lines that have not been accessed for a specific duration into a lowleakage standby mode. This duration is called the decay interval, and its optimal value varies across applications. This paper describes an adaptation technique that analytically finds the optimal decay interval through profiling, and shows that the most important variables required for finding the optimal decay interval can be estimated using profiling with a reasonable degree of accuracy. Unlike previous methods that attempt to put only �dead � lines into standby mode, this work explicitly trades off the leakage power saved in putting �live � lines into standby against its performance and energy costs. It also combines traditional DVS with cache decay using an analysis and obtains results close to what can be obtained with an omniscient choice of per-benchmark optimal decay interval. 1
Karthik Sankaranarayanan
Decay Study of {sup 257}Rf
The isotope {sup 257}Rf was produced in the fusion-evaporation reaction {sup 208}Pb({sup 50}Ti, n){sup 257}Rf. Reaction products were separated by the Argonne Fragment Mass Analyzer. Radioactive decay and spontaneous fission of {sup 257}Rf and its decay products were investigated. An isomeric state in {sup 257}Rf, with a half-life of 160{sub -31}{sup 42} {mu}S, was discovered by detecting internal conversion electrons followed by alpha decays. It is interpreted as a three-quasiparticle high-K isomer. A second group of internal-conversion electrons which were succeeded by alpha decay, with a half-life of 4.1{sub -1.3}{sup +2.4} s, was observed. These events might originate from the decay of excited states in {sup 257}Lr, populated by electron-capture decay of {sup 257}Rf, or from another isomer in {sup 257}Rf.
Qian, J.; Heinz, A.; Winkler, R. [Yale University, New Haven, CT 06511 (United States); Janssens, R. V. F.; Khoo, T. L.; Seweryniak, D.; Peterson, D.; Back, B. B.; Carpenter, M. P.; Greene, J. P.; Jiang, C. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; Pardo, R. C.; Robinson, A.; Scott, R.; Vondrasek, R.; Wang, X.; Zhu, S. [Argonne National Laboratory, Argonne, IL 60439 (United States)] (and others)
New Nuclear And Subnuclear Exotic Decays
In this paper new nuclear and subnuclear exotic decays are investigated. Some theoretical problems of the pionic radioactivity, such as fission-like models, applicable to all kind of exotic nuclear and subnuclear decays are presented. The induced nuclear and subnuclear decays are discussed. Moreover, using the recent results on the spontaneous fission half lives T of the heavy nuclei with Z new predictions on the pionic yields in the region of superheavy elements are presented.
D. B. Ion; Reveica Ion-Mihai; M. L. Ion
R Parity Violating Decays of the Gluino
Assuming the lightest supersymmetric particle is the gluino, we treat the decays gluino->quark-antiquark-neutrino and gluino->gluon-neutrino. Such couplings can be induced by the R parity violating quark-squark-lepton interaction which can also be responsible for neutrino masses and mixings. These R parity violating gluino decays have the same final state structure (jets plus missing energy) as previously considered decays into quark-antiquark-photino and gluon-gravitino but with significantly different gluino lifetimes.
L. Clavelli; H. Stremnitzer
Micromegas readouts for double beta decay searches
Double beta $\\beta\\beta$ decay experiments are one of the most active research topics in Neutrino Physics. The measurement of the neutrinoless mode $0\
Cebri�n, S; Ferrer-Ribas, E; Gal�n, J; Garc�a, J A; Giomataris, I; G�mez, H; Herrera, D C; Iguaz, F J; Irastorza, I G; Luz�n, G; Rodr�guez, A; Segu�, L; Tom�s, A
S. Cebri�n; T. Dafni; E. Ferrer-Ribas; J. Gal�n; J. A. Garc�a; I. Giomataris; H. G�mez; D. C. Herrera; F. J. Iguaz; I. G. Irastorza; G. Luz�n; A. Rodr�guez; L. Segu�; A. Tom�s
Particle decays and annihiliations - Electron positron annhiliation When an electron and positron (antielectron) collide at high energy, they can annihilate to produce charm...
Spectroscopy of element 115 decay chains
A high-resolution a, X-ray and -ray coincidence spectroscopy experiment was conducted at the GSI Helmholtzzentrum fu r Schwerionenforschung. Thirty correlated a-decay chains were detected following the fusion-evaporation reaction 48Ca + 243Am. The observations are consistent with previous assignments of similar decay chains to originate from element Z = 115. The data includes first candidates of fingerprinting the decay step Mt --> Bh with characteristic X rays. For the first time, precise spectroscopy allows the derivation of excitation schemes of isotopes along the decay chains starting with elements Z > 112. Comprehensive Monte-Carlo simulations accompany the data analysis. Nuclear structure models provide a first level interpretation.
Rudolph, Dirk [Lund University, Sweden; Forsberg, U. [Lund University, Sweden; Golubev, P. [Lund University, Sweden; Sarmiento, L. G. [Lund University, Sweden; Yakushev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Andersson, L.-L. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Di Nitto, A. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Duehllmann, Ch. E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Gates, J. M. [Lawrence Berkeley National Laboratory (LBNL); Gregorich, K. E. [Lawrence Berkeley National Laboratory (LBNL); Gross, Carl J [ORNL; Hessberger, F. P. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Herzberg, R.-D [University of Liverpool; Khuyagbaatar, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Kratz, J. V. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Rykaczewski, Krzysztof Piotr [ORNL; Schaedel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Aberg, S. [Lund University, Sweden; Ackermann, D. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Block, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Brand, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Carlsson, B. G. [Lund University, Sweden; Cox, D. [University of Liverpool; Derkx, X. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Eberhardt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Even, J. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Fahlander, C. [Lund University, Sweden; Gerl, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Jaeger, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kindler, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Krier, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kojouharov, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kurz, N. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Lommel, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mistry, A. [University of Liverpool; Mokry, C. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Nitsche, H. [Lawrence Berkeley National Laboratory (LBNL); Omtvedt, J. P. [Paul Scherrer Institut, Villigen, Switzerland; Papadakis, P. [University of Liverpool; Ragnarsson, I. [Lund University, Sweden; Runke, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schaffner, H. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schausten, B. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Thoerle-Pospiech, P. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Torres, T. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Traut, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Trautmann, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Tuerler, A. [Paul Scherrer Institut, Villigen, Switzerland; Ward, A. [University of Liverpool; Ward, D. E. [Lund University, Sweden; Wiehl, N. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany
Nuclear beta-decay measurements and |Vud|
Some recent work in nuclear beta decay related to the value of |Vud| is described along with some near-term goals for future measurements.
Dan Melconian
Melconian, Dan
Beta decays with momentum space Majorana spinors
We construct and apply to beta decays a truly neutral local quantum field that is entirely based upon momentum space Majorana spinors. We make the observation that theory with momentum space Majorana spinors of real C parities is equivalent to Dirac's theory. For imaginary C parities, the neutrino mass can drop from the single beta decay trace and reappear in 0\
M. Kirchbach; C. Compean; L. Noriega
Evidence for the suppressed decay B^- -> DK^-, D -> K^+?^-?^0
We report a study of the suppressed decay B^- -> DK^-, D -> K^+\\pi^-\\pi^0, where D denotes either a D^0 or a \\bar{D}^0 meson. The decay is sensitive to the CP-violating parameter \\phi_3. Using a data sample of 772 x 10^6 B\\bar{B} pairs collected at the \\Upsilon(4S) resonance with the Belle detector, we measure the ratio of branching fractions of the above suppressed decay to the favored decay B^- -> DK^-, D -> K^-\\pi^+\\pi^0. Our result is R_{DK} = [1.98 +/- 0.62(stat.) +/- 0.24(syst.)] x 10^{-2}, which indicates the first evidence of the signal for this suppressed decay with a significance of 3.2 standard deviations. We measure the direct CP asymmetry between the suppressed B^- and B^+ decays to be A_{DK} = 0.41 +/- 0.30 (stat.) +/- 0.05 (syst.). We also report measurements for the analogous quantities R_{D\\pi} and A_{D\\pi} for the decay B^- -> D\\pi^-, D -> K^+\\pi^-\\pi^0.
Belle Collaboration; M. Nayak; J. Libby; K. Trabelsi; I. Adachi; H. Aihara; D. M. Asner; T. Aushev; A. M. Bakich; A. Bala; P. Behera; K. Belous; V. Bhardwaj; G. Bonvicini; A. Bozek; M. Bra?ko; T. E. Browder; D. ?ervenkov; M. -C. Chang; P. Chang; V. Chekelian; A. Chen; B. G. Cheon; R. Chistov; I. -S. Cho; K. Cho; V. Chobanova; Y. Choi; D. Cinabro; J. Dalseno; M. Danilov; Z. Dole�al; Z. Dr�sal; D. Dutta; S. Eidelman; S. Esen; H. Farhat; J. E. Fast; T. Ferber; V. Gaur; N. Gabyshev; S. Ganguly; R. Gillard; Y. M. Goh; B. Golob; J. Haba; H. Hayashii; Y. Horii; Y. Hoshi; W. -S. Hou; H. J. Hyun; T. Iijima; A. Ishikawa; T. Iwashita; I. Jaegle; T. Julius; D. H. Kah; E. Kato; D. Y. Kim; H. J. Kim; J. B. Kim; M. J. Kim; Y. J. Kim; K. Kinoshita; J. Klucar; B. R. Ko; P. Kody�; S. Korpar; P. Krishnan; P. Kri�an; P. Krokovny; T. Kuhr; T. Kumita; A. Kuzmin; Y. -J. Kwon; S. -H. Lee; J. Li; Y. Li; L. Li Gioi; Y. Liu; D. Liventsev; P. Lukin; H. Miyake; R. Mizuk; G. B. Mohanty; A. Moll; T. Mori; N. Muramatsu; R. Mussa; Y. Nagasaka; M. Nakao; E. Nedelkovska; K. Negishi; C. Ng; N. K. Nisar; O. Nitoh; S. Ogawa; S. Okuno; Y. Onuki; P. Pakhlov; G. Pakhlova; C. W. Park; H. Park; T. K. Pedlar; M. Petri?; L. E. Piilonen; M. Ritter; M. R�hrken; A. Rostomyan; H. Sahoo; T. Saito; Y. Sakai; S. Sandilya; L. Santelj; T. Sanuki; V. Savinov; O. Schneider; G. Schnell; C. Schwanda; A. J. Schwartz; K. Senyo; O. Seon; M. E. Sevior; M. Shapkin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; Y. -S. Sohn; A. Sokolov; E. Solovieva; M. Stari?; M. Steder; Z. Suzuki; U. Tamponi; G. Tatishvili; Y. Teramoto; M. Uchida; T. Uglov; Y. Unno; S. Uno; P. Urquijo; S. E. Vahsen; C. Van Hulse; P. Vanhoefer; G. Varner; K. E. Varvell; M. N. Wagner; C. H. Wang; M. -Z. Wang; Y. Watanabe; K. M. Williams; E. Won; Y. Yamashita; S. Yashchenko; Y. Yusa; V. Zhilich; V. Zhulanov; A. Zupanc
The decay rate of ocean swell observed by altimeter
Altimeter data from transects across the Southern Ocean is analysed to determine the decay of oceanic swell. The resulting decay rate is shown to be proportional to wave number squared and swell amplitude cubed. Such a decay relationship is ...
I. R. Young; A. V. Babanin; S. Zieger
Semileptonic Decays and Sides of the Unitarity Triangle
The elements of the CKM matrix enter the expressions for the decay rates and mixing amplitudes of hadrons. In some cases, the theoretical expressions are free of strong interaction effects, for example the CP asymmetry in B {yields} J/{psi} K{sub S}{sup 0}, so that measuring the CP asymmetry directly gives the value of sin 2{beta}, with the error in the result given by the experimental error in the measurement. In most cases, however, the experimentally measured quantities depend on strong interactions physics, and it is absolutely essential to have accurate model-free theoretical calculations to compare with experiment. A number of theoretical tools have been developed over the years which now allow us to compute B decays with great accuracy, sometimes at the level of a few percent or better. These calculations are done using effective theory methods applied to QCD, and do not rely on model assumptions. Inclusive decays can be treated using the operator product expansion (OPE). The total decay rate is given by twice the imaginary part of the forward scattering amplitude, using the optical theorem. In heavy hadron decays, the intermediate states in the forward scattering amplitude can be integrated out, so that the decay rate can be written as an expansion in local operators. The expansion parameter is 1/m{sub B}, the mass of the decaying hadron. OPE techniques have been well-studied in the context of deep-inelastic scattering, where the expansion in powers of 1/Q{sup 2} is called the twist expansion. In inclusive B decays, the leading term in the 1/m{sub B} expansion gives the parton decay rate, and nonperturbative effects enter at higher orders in 1/m{sub B}.
Ligeti, Zoltan; Bauer, C.; Bernard, C.; Bigi, I.; Datta, M.; del Re, D.; Grinstein, B.; Hashimoto, S.; Langenegger, U.; Ligeti, Z.; Luke, M.; Lunghi, E.; Mackenzie, P.; Manohar, A.; Moore, T.; Pirjol, D.; Robertson, S.; Rothstein, I.; Stewart, I.; Voloshin, M.
delta S = 2 nonleptonic hyperon decays
A sensitive search for the rare decays \\Omega^- \\to \\Lambda \\pi^- and \\Xi^0 \\to p \\pi^- has been performed using data from the 1997 run of the HyperCP (Fermilab E871) experiment. Limits on other such processes do not exclude the possibility of observable rates for |\\Delta S| = 2 nonleptonic hyperon decays, provided the decays occur through parity-odd operators. We obtain the branching-fraction limits B(\\Omega^- \\to \\Lambda \\pi^-)< 2.9 x 10^{-6} and B(\\Xi^0 \\to p \\pi^-)< 8.2 x 10^{-6}, both at 90% confidence level.
C. G. White; R. A. Burnstein; A. Chakravorty; A. Chan; Y. C. Chen; W. S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; G. Gidal; P. Gu; H. R. Gustafson; C. Ho; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; D. M. Kaplan; L. M. Lederman; N. Leros; M. J. Longo; F. Lopez; L. C. Lu; W. Luebke; K. B. Luk; K. S. Nelson; H. K. Park; J. -P. Perroud; D. Rajaram; H. A. Rubin; P. K. Teng; J. Volk; S. L. White; P. Zyla
White, C G; Chakravorty, A; Chan, A; Chen, Y C; Choong, W S; Clark, K; Dukes, E C; Durandet, C; F�lix, J; Gidal, G; Gu, P; Gustafson, H R; Ho, C; Holmstrom, T; Huang, M; James, C; Jenkins, C M; Kaplan, D M; Lederman, Leon Max; Leros, Nicolas; Longo, M J; L�pez, F; Lu, L C; Luebke, W; Luk, K B; Nelson, K S; Park, H K; Perroud, Jean-Pierre; Rajaram, D; Rubin, H A; Teng, P K; Volk, J; White, S L; Zyla, P
Suppressed $B_s$ decays at CDF
We review three recent results of the CDF collaboration on B{sub s}{sup 0} suppressed decays: the first search for CP-violation in the B{sub s}{sup 0} {yields} {phi}{phi} decay, where two CP-violating asymmetries expected to be zero in the Standard Model are measured, and the observation and the branching ratio measurements of B{sub s}{sup 0} {yields} J/{Psi} f{sub 0}(980) and B{sub s}{sup 0} {yields} J/{Psi} K{sup (*)} decays.
Dorigo, Mirco
Simple model for decay of superdeformed nuclei
Recent theoretical investigations of the decay mechanism out of a superdeformed nuclear band have yielded qualitatively different results, depending on the relative values of the relevant decay widths. We present a simple two-level model for the dynamics of the tunneling between the superdeformed and normal-deformed bands, which treats decay and tunneling processes on an equal footing. The previous theoretical results are shown to correspond to coherent and incoherent limits of the full tunneling dynamics. Our model accounts for experimental data in both the A~150 mass region, where the tunneling dynamics is coherent, and in the A~190 mass region, where the tunneling dynamics is incoherent.
C. A. Stafford; B. R. Barrett
Higgs boson decay to mu mubar gamma
The Higgs boson decay, H -> mu mubar gamma, is studied in the Standard Model at the tree and one-loop levels. It is shown that for Higgs boson masses above 110 GeV, the contribution to the radiative width from the one-loop level exceeds the contribution from the tree level, and for Higgs boson masses above 140 GeV, it even exceeds the contribution from the tree level decay H -> mu mubar. We also show that the contributions to the radiative decay width from the interference terms between the tree and one-loop diagrams are negligible.
Ali Abbasabadi; Wayne W. Repko
Semileptonic B / Bs decays at Belle
The Belle experiment at the KEKB asymmetric energy e+e- collider recorded large data sets of both, B and Bs decays. Semileptonic decays B(s) -> X l nu (l = electron or muon) constitute approximately one fifth of the total decay width of B(s) mesons and play an important role in the determination of the CKM matrix elements V_ub and V_cb. Recent results from Belle are presented, including the study of B- -> Ds(*) K l nu, the first measurements of semi-inclusive modes B -> D(*) X l nu and the measurement of the inclusive branching fraction Bf(Bs -> X l nu).
Christian Oswald
Decay heat is an important parameter in reactor design. Fission products generate heat in the reactor core even when the reactor has shut down. This heat has potential to melt the core if heat removal is not sufficient, and it is what caused the accident in Japan last year. Thus, decay heat must be considered in reactor design for safety. The research focused on decay heat conditions of current and next generation reactors. US-APWR, ABWR, VHTR, and ABR were modeled and simulated using the program SCALE. When the reactors were simulated to operate for two years and cool down for one year, the ABR produced the most decay heat power during operation and cooling time, and the US-APWR, VHTR, and ABWR followed respectfully. Therefore, the ABR requires more coolant and cooling time than other reactors, and the ABWR requires the least.
Choe, JongSoo 1985-
The Particle Adventure | Particle decays and annihiliations | Confusion
Confusion about Confusion about decays Confusion about decays Many heavy elements decay into simpler things. But a close observation of these decays reveals several confusing problems. Consider uranium-238 decay. A lump of uranium-238 will decay at a constant rate such that in 4,460,000,000 years -- give or take a few days -- half the uranium will be gone. But there is no way to tell when a specific uranium atom will decay; it could decay five minutes from now, or in ten billion years. Why will an atom decay only according to some probability? Uranium-238 has a mass of 238.0508 atomic mass units (u). It can decay into thorium (234.0436 u) and an alpha particle (4.0026 u). But uranium's mass minus the mass of its decay products is 0.0046 u. Why is there missing mass?
Effective field theories for inclusive B decays
In this thesis, we study inclusive decays of the B meson. These allow one to determine CKM elements precisely and to search for physics beyond the Standard Model. We use the framework of effective field theories, in ...
Lee, Keith S. M. (Keith Seng Mun)
The Albedo Decay of Prairie Snows
Daily albedos of snow were measured between November and April, 1969�87, and were analyzed to determine the decay rate between snowfalls. The data essentially represent the snow accumulation season because the analysis was limited to days when ...
D. G. Baker; D. L. Ruschy; D. B. Wall
Alpha decay favoured isotopes of some superheavy nuclei: Spontaneous fission versus alpha decay
Spontaneous fission and alpha decay are the main decay modes for superheavy nuclei. The superheavy nuclei which have small alpha decay half-life compared to spontaneous fission half-life will survive fission and can be detected in the laboratory through alpha decay. We have studied the alpha decay half-life and spontaneous half-life of some superheavy elements in the atomic range Z = 100-130. Spontaneous fission half-lives of superheavy nuclei have been calculated using the phenomenological formula and the alpha decay half-lives using Viola-Seaborg-Sobiczewski formula (Sobiczewski et al. 1989), semi empirical relation of Brown (1992) and formula based on generalized liquid drop model proposed by Dasgupta-Schubert and Reyes (2007). The results are reported here.
O. V. Kiren; S. B. Gudennavar; S. G. Bubbly
Anomalous Radiative Decay of Heavy Higgs Boson
The radiative decay width of a heavy Higgs boson $H \\rightarrow W^+W^-\\gamma$ for a {\\it hard} photon is calculated in the Standard Model and its extension with anomalous $\\gamma WW$ couplings. Its dependence on the Higgs mass, the two unknown anomalous couplings, and the photon energy cutoff are studied in detail. We show that this radiative decay of a heavy Higgs is not very sensitive to a wide range of the anomalous couplings compared to the Standard Model result.
Tzu Chiang Yuan
Passive Core Decay Heat Removal Performance Guideline
Passive decay heat removal systems operate without pumps when normal heat removal systems are not available. Safety is ensured by confirming that an adequate thermal margin is provided to accommodate various operating conditions, design uncertainties, and degradation. Guidelines to ensure adequate thermal performance are provided for three different system configurations.This report introduces utility systems engineers to the design and operation of passive decay heat removal systems and ...
Rare B Meson Decays at the Tevatron
Rare B meson decays are an excellent probe for beyond the Standard Model physics. Two very sensitive processes are the b {yields} s{mu}{sup +}{mu}{sup -} and B{sub s,d}{sup 0} {yields} {mu}{sup +}{mu}{sup -} decays. We report recent results at a center of mass energy of {radical}s = 1.96 TeV from CDF II using 7 fb{sup -1} at the Fermilab Tevatron Collider.
Hopkins, Walter
Competition between alpha-decay and beta-decay for Heavy and Superheavy Nuclei
In this work, the $\\beta$-stable region for Z $\\geq$ 90 is proposed. The calculated $\\beta$-stable nuclei in the $\\beta$-stable region are in good agreement with the ones obtained by M\\"{o}ller \\emph{et al}.. The half-lives of the nuclei close to the $\\beta$-stable region are calculated and the competition between $\\alpha$-decay and $\\beta$-decay is systematically investigated. The calculated half-lives and the suggested decay modes are well in line with the experimental results. The predictions for half-lives and decay modes of the nuclei with Z = 107$-$110 are presented.
Zongqiang Sheng; Liangping Shu; Ying Meng; Jigang Hu; Jianfa Qian
On the ability of Order Statistics to distinguish different models for continuum gamma decay
A simulation procedure to calculate some important parameters to the application of Order Statistics in the analysis of continuum gamma decay is presented.
Sandoval, J. J.; Cristancho, F. [Departamento de Fisica, Universidad Nacional de Colombia, Bogota (Colombia); Centro Internacional de Fisica, Bogota (Colombia)
Spectrum and decays of kaonic hydrogen
By using the non-relativistic effective Lagrangian approach to bound states, a complete expression for the isospin-breaking corrections to the energy levels and the decay widths of kaonic hydrogen is obtained up-to-and-including O(alpha,m_d-m_u) in QCD. It is demonstrated that, although the leading-order corrections at O(alpha^{1/2},(m_d-m_u)^{1/2}) emerging due to the unitarity cusp, are huge, they can be expressed solely in terms of the KN S-wave scattering lengths. Consequently, at leading order, it is possible to derive parameter-free modified Deser-type relations, which can be used to extract the scattering lengths from the hadronic atom data.
Ulf-G. Meissner; Udit Raha; Akaki Rusetsky
Search for Hadronic Decays of a Light Higgs Boson in the Radiative Decay ???A?
We search for hadronic decays of a light Higgs boson (A?) produced in radiative decays of an ?(2S) or ?(3S) meson, ???A?. The data have been recorded by the BABAR experiment at the ?(3S) and ?(2S) center-of-mass energies ...
Cowan, Ray Franklin
Parametric Decay during HHFW on NSTX
DOE Green Energy (OSTI)
High Harmonic Fast Wave (HHFW) heating experiments on NSTX have been observed to be accompanied by significant edge ion heating (T{sub i} >> T{sub e}). This heating is found to be anisotropic with T{sub perp} > T{sub par}. Simultaneously, coherent oscillations have been detected with an edge Langmuir probe. The oscillations are consistent with parametric decay of the incident fast wave ({omega} > 13{omega}{sub ci}) into ion Bernstein waves and an unobserved ion-cyclotron quasi-mode. The observation of anisotropic heating is consistent with Bernstein wave damping, and the Bernstein waves should completely damp in the plasma periphery as they propagate toward a cyclotron harmonic resonance. The number of daughter waves is found to increase with rf power, and to increase as the incident wave's toroidal wavelength increases. The frequencies of the daughter wave are separated by the edge ion cyclotron frequency. Theoretical calculations of the threshold for this decay in uniform plasma indicate an extremely small value of incident power should be required to drive the instability. While such decays are commonly observed at lower harmonics in conventional ICRF heating scenarios, they usually do not involve the loss of significant wave power from the pump wave. On NSTX an estimate of the power loss can be found by calculating the minimum power required to support the edge ion heating (presumed to come from the decay Bernstein wave). This calculation indicates at least 20-30% of the incident rf power ends up as decay waves.
J.R. Wilson; S. Bernabei; T. Biewer; S. Diem; J. Hosea; B. LeBlanc; C.K. Phillips; P. Ryan; D.W. Swain
Factorization in B ---> V gamma decays
The factorization properties of the radiative decays B {yields} V{gamma} are analyzed at leading order in 1/m{sub b} using the soft-collinear effective theory. It is shown that the decay amplitudes can be expressed in terms of a B {yields} V form factor evaluated at q{sup 2} = 0, light-cone distribution amplitudes of the B and V mesons, and calculable hard-scattering kernels. The renormalization-group equations in the effective theory are solved to resum perturbative logarithms of the different scales in the decay process. Phenomenological implications for the B {yields} K*{gamma} branching ratio, isospin asymmetry, and CP asymmetries are discussed, with particular emphasis on possible effects from physics beyond the Standard Model.
Becher, Thomas; /Fermilab; Hill, Richard J.; /SLAC; Neubert, Matthias; /Cornell U., LEPP
Exclusive Double Charmonium Production from $?$ Decay
The exclusive decay of $\\Upsilon$ to a vector plus pseudoscalar charmonium is studied in perturbative QCD. The corresponding branching ratios are predicted to be of order $10^{-6}$ for first three $\\Upsilon$ resonances, and we expect these decay modes should be discovered in the prospective high-luminosity $e^+e^-$ facilities such as super $B$ experiment. As a manifestation of the short-distance loop contribution, the relative phases among strong, electromagnetic and radiative decay amplitudes can be deduced. It is particularly interesting to find that the relative phase between strong and electromagnetic amplitudes is nearly orthogonal. The resonance-continuum interference effect for double charmonium production near various $\\Upsilon$ resonances in $e^+e^-$ annihilation is addressed.
Yu Jia
{delta}L=2 hyperon semileptonic decays
We compute the rates of semileptonic B{sub A}{yields}B{sub B}l{sup -}l{sup -} (l=e or {mu}) hyperon transitions in a model where intermediate states involve loops of baryons and a Majorana neutrino. These rates turn out to be well below present experimental bounds and other theoretical estimates. From the experimental upper limit on the {xi}{sup -}{yields}p{mu}{sup -}{mu}{sup -} decay, we derive the bound {<=}22 TeV for the effective Majorana mass of the muon neutrino. Also, an estimate of background contributions for these decays due to the allowed B{sub A}{yields}B{sub B}l{sup -}l{sup -}{nu}{nu} decays is provided.
Barbero, C.; Mariano, A. [Departamento de Fisica, Universidad Nacional, de La Plata, cc 67, 1900 La Plata (Argentina); Li, Ling-Fong [Department of Physics, Carnegie Mellon University, Pittsburg, Pennsylvania 15213 (United States); Castro, G. Lopez [Departamento de Fisica, Cinvestav, Apartado Postal 14-740, 07000 Mexico D.F. (Mexico)
Lepton Flavor Violating Decays - Review & Outlook
Here I review the status and prospects of experimental investigations into lepton flavor violation (LFV) in charged leptons. Rare LFV processes are naturally expected to occur through loops of TeV scale particles predicted by supersymmetric theories or other models beyond the Standard Model. In contrast to physics of quark flavors that is dominated by the Cabibbo-Kobayashi-Maskawa matrix, LFV in charged leptons is a definitive signal of new physics. Currently active researches are rare tau decay searches at the B factories. The MEG experiment will soon start a sensitive search for the LFV muon decay, mu to e gamma. Prospects for searches at the LHC, a possibility of a fixed target LFV experiment with high energy muons, and a sensitivity of leptonic kaon decays to LFV are also briefly discussed.
Toshinori Mori
New results for rare muon decays
Branching-ratio limits obtained with the Crystal Box detector are presented for the rare muon decays ..mu.. ..-->.. eee, ..mu.. ..-->.. e..gamma.., and ..mu.. ..-->.. e..gamma gamma... These decays, which violate the conservation of separate lepton-family numbers, are expected to occur in many extensions to the standard model. We found no candidates for the decay ..mu.. ..-->.. eee, yielding an upper limit for the branching ratio of B/sub ..mu..3e/ .. e..gamma.. candidates yields an upper limit of B/sub ..mu..e..gamma../ .. e..gamma gamma.. candidates gives an upper limit of B/sub ..mu..e..gamma gamma../ < 7.2 x 10/sup -11/. These results strengthen the constraints on models that allow transitions between lepton families.
Mischke, R.E.; Bolton, R.D.; Bowman, J.D.; Cooper, M.D.; Frank, J.S.; Hallin, A.L.; Heusi, P.A.; Hoffman, C.M.; Hogan, G.E.; Mariam, F.G.
Chiral approach to Phi Radiative Decays
(980) and f0(980) according to ? ? f0, a0 + ? and hence are generally considered to provide valuable information about the puzzling light scalar mesons[2] of low energy QCD. The theoretical analysis of this type of decay was initiated by Achasov and Ivanchenko... [3] and followed up by many others [4]. The starting point was the observation that the ? meson decays about 50 per cent of the time into K+K?. Since this final state can easily annihilate to produce either an f0 or a0 together with an emitted photon...
Black, Deirdre; Harada, Masayasu; Shechter, Joseph
Neutrinoless double beta decay and neutrino masses
Neutrinoless double beta decay (0{nu}{beta}{beta}) is a promising test for lepton number violating physics beyond the standard model (SM) of particle physics. There is a deep connection between this decay and the phenomenon of neutrino masses. In particular, we will discuss the relation between 0{nu}{beta}{beta} and Majorana neutrino masses provided by the so-called Schechter-Valle theorem in a quantitative way. Furthermore, we will present an experimental cross check to discriminate 0{nu}{beta}{beta} from unknown nuclear background using only one isotope, i.e., within one experiment.
Duerr, Michael [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany)
The double-beta decay: Theoretical challenges
Neutrinoless double beta decay is a unique process that could reveal physics beyond the Standard Model of particle physics namely, if observed, it would prove that neutrinos are Majorana particles. In addition, it could provide information regarding the neutrino masses and their hierarchy, provided that reliable nuclear matrix elements can be obtained. The two neutrino double beta decay is an associate process that is allowed by the Standard Model, and it was observed for about ten nuclei. The present contribution gives a brief review of the theoretical challenges associated with these two process, emphasizing the reliable calculation of the associated nuclear matrix elements.
Horoi, Mihai [Department of Physics, Central Michigan University, Mount Pleasant, Michigan, 48859 (United States)
Scintillating bolometers for Double Beta Decay search
In the field of Double Beta Decay (DBD) searches, the use of high resolution detectors in which background can be actively discriminated is very appealing. Scintillating bolometers containing a Double Beta Decay emitter can largely fulfill this very interesting possibility. In this paper we present the latest results obtained with CdWO4 and CaMoO4 crystals. Moreover we report, for the first time, a very interesting feature of CaMoO4 bolometers: the possibility to discriminate beta-gamma events from those induced by alpha particles thanks to different thermal pulse shape.
Gironi, Luca
Luca Gironi
Higgs decay into diphoton in Composite Higgs Model
We explore the Higgs couplings to gauge bosons in the minimal $SO(5)/SO(4)$ 4D composite Higgs model. The pions scatterings put unitary constraints on the couplings therefore determine the branch ratios of various Higgs decays. Through fine tuning the parameters, enhancement of Higgs to diphoton rate is possible to be achieved with the existence of vector meson fields.
Cai, Haiying
Observation of Parity Violation in the Omega-minus -> Lambda + K-minus Decay
The alpha decay parameter in the process Omega-minus -> Lambda + K-minus has been measured from a sample of 4.50 million unpolarized Omega-minus decays recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78 +/- 0.19(stat) +/- 0.16(syst)]{\\times}10^{-2}. This is the first unambiguous evidence for a nonzero alpha decay parameter, and hence parity violation, in the Omega-minus -> Lambda + K-minus decay.
Lu, L C; Chakravorty, A; Chen, Y C; Choong, W S; Clark, K; Dukes, E C; Durandet, C; F�lix, J; Fu, Y; Gidal, G; Gustafson, H R; Holmstrom, T; Huang, M; James, C; Jenkins, C M; Jones, T D; Kaplan, D M; Longo, M J; Luebke, W; Luk, K B; Nelson, K S; Park, H K; Perroud, Jean-Pierre; Rajaram, D; Rubin, H A; Volk, J; White, C G; White, S L; Zyla, P
HyperCP Collaboration; L. C. Lu; R. A. Burnstein; A. Chakravorty; Y. C. Chen; W. -S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; H. R. Gustafson; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; T. D. Jones; D. M. Kaplan; M. J. Longo; W. Luebke; K. -B. Luk; K. S. Nelson; H. K. Park; J. -P. Perroud; D. Rajaram; H. A. Rubin; J. Volk; C. G. White; S. L. White; P. Zyla
Review of K$sup 0$ decays
From meeting of the division of particles and fields; Berkeley, California, USA (13 Aug 1973). A review is given of selected topics in K/sup 0/ decays for which recent results have led to substantial progress and/or cortroversy. (auth)
Nygren, D.R.
Light Hadron Masses and Decay Constants
The extraction of the light hadron spectrum from a first-principle Quantum Chromodynamics approach is a profound application for lattice simulations of Quantum Chromodynamics. This review will cover recent lattice results for the masses and decay constants of the light hadrons. In particular, the applicability of different approaches for the extrapolation towards the physical point will be discussed.
Enno E. Scholz
Anatomy of neck configuration in fission decay
The anatomy of neck configuration in the fission decay of Uranium and Thorium isotopes is investigated in a microscopic study using Relativistic mean field theory. The study includes $^{236}U$ and $^{232}Th$ in the valley of stability and exotic neutron rich isotopes $^{250}U$, $^{256}U$, $^{260}U$, $^{240}Th$, $^{250}Th$, $^{256}Th$ likely to play important role in the r-process nucleosynthesis in stellar evolution. Following the static fission path, the neck configurations are generated and their composition in terms of the number of neutrons and protons are obtained showing the progressive rise in the neutron component with the increase of mass number. Strong correlation between the neutron multiplicity in the fission decay and the number of neutrons in the neck is seen. The maximum neutron-proton ratio is about 5 for $^{260}$U and $^{256}$Th suggestive of the break down of liquid-drop picture and inhibition of the fission decay in still heavier isotopes. Neck as precursor of a new mode of fission decay like multi-fragmentation fission may also be inferred from this study.
S. K. Patra; R. K. Choudhury; L. Satpathy
Search for the decay B0???
We report the result of a search for the rare decay B0??? [B superscript 0???] in 426??fb-1 [fb superscript -1] of data, corresponding to 226�106 B0B? 0 [226 x 10 superscript 6 B superscript 0 B? superscript 0] pairs, ...
Nuclear physics aspects of double beta decay
Comprehensive description of the phenomenology of the $\\beta\\beta$ decay is given, with emphasis on the nuclear physics aspects. After a brief review of the neutrino oscillation results and of motivation to test the lepton number conservation, the mechanism of the $0\
Petr Vogel
Decay of a Near-Inertial Wave
The decay of a downward propagating near-inertial wave was observed over four days. During this short period, the energy of the near-inertial wave decreased by 70%. The shear layers produced by the wave were regions of enhanced turbulent ...
Dave Hebert; J. N. Moum
Comparing radiative and recoil corrections in neutron beta-decay and inverse beta-decay
The inverse $\\beta$-decay reaction, anti-nu_e + p --> e^+ + n, for low-energy anti-neutrinos coming from nuclear reactors is of great current interest in connection with high-precision measurements of the neutrino mixing angle $\\theta_{13}$. We have previously derived analytic expressions, up to next-to-leading order in heavy-baryon chiral perturbation theory, for the radiative corrections (RCs) and the nucleon-recoil corrections both for this reaction and for the related neutron $\\beta$-decay process. We investigate here the numerical consequences of these analytic expressions. We show that the recoil corrections are small for neutron $\\beta$-decay, but for inverse $\\beta$-decay, the recoil corrections are comparable in size to the RCs for typical energies of reactor anti-neutrinos, and they have opposite signs. It turns out that the RCs and the recoil corrections exhibit very different dependences on the neutrino energy.
Raha, U; Kubodera, K
Discovering a Higgs boson decaying to four jets in supersymmetric cascade decays
The Higgs boson may dominantly decay to four light jets through a light pseudoscalar intermediary: h{yields}2{eta}{yields}4j, making reconstruction at the LHC particularly challenging. We explore the phenomenology of such ''buried Higgs'' scenarios in which the primary discovery channel of the Higgs is in cascade decays of superpartners. QCD backgrounds that would otherwise overwhelm the Higgs decay are suppressed by the requirement of high p{sub T} jets and large missing transverse momentum that are the typical signatures of TeV scale supersymmetry. Utilizing jet substructure techniques, we find that for buried Higgses in the 100-120 GeV range, a 5{sigma} discovery can be expected with roughly 10-25 fb{sup -1} of data at E{sub CM}=14 TeV. For lighter Higgs bosons, the signal is contaminated by hadronically decaying W bosons, and discovery remains an unsolved challenge.
Bellazzini, Brando; Csaki, Csaba [Institute for High Energy Phenomenology, Newman Laboratory of Elementary Particle Physics, Cornell University, Ithaca, New York 14853 (United States); Hubisz, Jay; Shao, Jing [201 Physics Building, Syracuse University, Syracuse, New York 13244 (United States)
U. Raha; F. Myhrer; K. Kubodera
A Statistical Plume Model with First-Order Decay
Many atmospheric contaminants decay or react in the atmosphere. in situations such as the diffusion of radioactive contaminants, certain chemical pollutants and viable microorganisms, a first-order decay rate is considered to be an appropriate ...
Thomas J. Overcamp
CP violation in B decays
She reviews how one can test the Standard Model predictions for CP violation. This test requires sufficient independent measurements to overconstrain the model parameters and thus be sensitive to possible beyond Standard Model contributions. She addresses the challenges for theory as well as for experiment to achieve such a test.
Quinn, H.R.
Search for ? + / EC double beta decay of 120 Te
We present a search for ? + / EC double beta decay of 120 Te performed with the CUORICINO experiment
C. Tomei; The CUORICINO Collaboration
Reheating induced by competing decay modes
We address the problem of studying the decay of the inflaton field {phi} to another scalar field {chi} through parametric resonance in the case of a coupling that involves several decay modes. This amounts to the presence of extra harmonic terms in the perturbation of the {chi} field dynamics. For the case of two frequencies we compute the geometry of the resonance regions, which is significantly altered due to the presence of noncuspidal resonance regions associated to higher harmonics and to the emergence of instability 'pockets'. We discuss the effect of this change in the efficiency of the energy transfer process for the simplest case of a coupling given by a combination of the two interaction terms of homogeneous degree usually considered in the literature. We find that the presence of higher harmonics has limited cosmological implications.
Charters, T. [Departamento de Engenharia Mecanica/Area Cientifica de Matematica, Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1, P-1949-014 Lisbon, Portugal and Centro de Fisica Teorica e Computacional da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon (Portugal); Nunes, A.; Mimoso, J. P. [Departamento de Fisica, Faculdade de Ciencias da Universidade de Lisboa, Centro de Fisica Teorica e Computacional da Universidade de Lisboa, Avenida Professor Gama Pinto 2, P-1649-003 Lisbon (Portugal)
Time reversal invariance in polarized neutron decay
An experiment to measure the time reversal invariance violating (T-violating) triple correlation (D) in the decay of free polarized neutrons has been developed. The detector design incorporates a detector geometry that provides a significant improvement in the sensitivity over that used in the most sensitive of previous experiments. A prototype detector was tested in measurements with a cold neutron beam. Data resulting from the tests are presented. A detailed calculation of systematic effects has been performed and new diagnostic techniques that allow these effects to be measured have been developed. As the result of this work, a new experiment is under way that will improve the sensitivity to D to 3 {times} 10{sup {minus}4} or better. With higher neutron flux a statistical sensitivity of the order 3 {times} 10{sup {minus}5} is ultimately expected. The decay of free polarized neutrons (n {yields} p + e + {bar v}{sub e}) is used to search for T-violation by measuring the triple correlation of the neutron spin polarization, and the electron and proton momenta ({sigma}{sub n} {center_dot} p{sub p} {times} p{sub e}). This correlation changes sign under reversal of the motion. Since final state effects in neutron decay are small, a nonzero coefficient, D, of this correlation indicates the violation of time reversal invariance. D is measured by comparing the numbers of coincidences in electron and proton detectors arranged symmetrically about a longitudinally polarized neutron beam. Particular care must be taken to eliminate residual asymmetries in the detectors or beam as these can lead to significant false effects. The Standard Model predicts negligible T-violating effects in neutron decay. Extensions to the Standard Model include new interactions some of which include CP-violating components. Some of these make first order contributions to D.
Wasserman, E.G.
Nuclear decay data for selected radionuclides
Contained in this report are tabulations of the atomic and nuclear radiations emitted by 194 radioactive nuclides. The nuclei included comprise most of those currently of interest in medical practice or research, health physics, industry, nuclear power, environmental impact studies, and as reference standards. Listed in tabular form are recommended values for half-lives, energies, intensities (probabilities per decay), and equilibrium absorbed-dose constants for each of the atomic and nuclear radiations emitted by these radioactive atoms. (auth)
Martin, M.J. (ed.)
Proton decay matrix elements from lattice QCD
We report on the calculation of the matrix elements of nucleon to pseudoscalar decay through a three quark operator, a part of the low-energy, four-fermion, baryon-number-violating operator originating from grand unified theories. The direct calculation of the form factors using domain-wall fermions on the lattice, incorporating the u, d and s sea-quarks effects yields the results with all the relevant systematic uncertainties controlled for the first time.
Aoki, Yasumichi; Shintani, Eigo [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI), Nagoya University, Nagoya 464-8602 (Japan); RIKEN-BNL Research Center, Brookhaven National Laboratory, Upton, New York 11973 (United States); Collaboration: RBC Collaboration; UKQCD Collaboration
Effects of light scalar mesons in $?\\to 3?$ decay
We study the role of a possible nonet of light scalar mesons in the still interesting $\\eta \\to 3\\pi$ decay process, with the primary motivation of learning more about the scalars themselves. The framework is a conventional non-linear chiral Lagrangian of pseudoscalars and vectors, extended to include the scalars. The parameters involving the scalars were previously obtained to fit the s-wave $\\pi\\pi$ and $\\pi$K scatterings in the region up to about 1 GeV as well as the strong decay $\\eta' \\to \\eta \\pi\\pi$. At first, one might expect a large enhancement from diagrams including a light $\\sigma(560)$. However there is an amusing cancellation mechanism which prevents this from occurring. In the simplest model there is an enhancement of about 13 per cent in the \\e3p decay rate due to the scalars. In a more complicated model which includes derivative type symmetry breakers, the cancellation is modified and the scalars contribute about 30 percent of the total decay rate (although the total is not significantly changed). The vectors do not contribute much. Our model produces a reasonable estimate for the related $a_0(980)-f_0(980)$ mixing strength, which has been a topic of current debate. Promising directions for future work along the present line are suggested.
Abdou M. Abdel-Rehim; Deirdre Black; Amir H. Fariborz; Joseph Schechter
Search for Exclusive Charmless Hadronic B Decays
We have searched for several two-body charmless hadronic decays of B mesons. These final states include K and with both charged and neutral kaons and pions; K , Kae, and ae; and OEX s , where X s = K; K , or OE. The data used in this analysis consist of 2:0 fb \\Gamma1 taken on the \\Upsilon(4S ) with the CLEO-II detector at the Cornell Electron Storage Ring (CESR). This data set includes 2.2 million BB pairs, allowing us to place upper limits on these branching ratios in the range from 10 \\Gamma4 to 10 \\Gamma5 . Permanent address: University of Hawaii at Manoa y Permanent address: INP, Novosibirsk, Russia 2 I. INTRODUCTION The decays of B-mesons to two charmless hadrons can proceed via a b ! u tree-level spectator diagram (Figure 1a), or via a b ! sg one-loop "penguin-diagram" (Figure 1b) and to a lesser extent, via the CKM-suppressed b ! dg penguin diagram. Although rare decays can also proceed via b ! u internal, color-suppressed diagrams (Figure 1c), b ! u exch...
Gronberg Kutschke Menary; Ichep Ref; Gsl Cleo Conf; Search Exclusive; Charmless Hadronic; B Decays; S. Menary; S. Nakanishi; C. Qiao
A background free double beta decay experiment
We present a new detection scheme for rejecting backgrounds in neutrino less double beta decay experiments. It relies on the detection of Cherenkov light emitted by electrons in the MeV region. The momentum threshold is tuned to reach a good discrimination between background and good events. We consider many detector concepts and a range of target materials. The most promising is a high-pressure 136Xe emitter for which the required energy threshold is easily adjusted. Combination of this concept and a high pressure Time Projection Chamber could provide an optimal solution. A simple and low cost effective solution is to use the Spherical Proportional Counter that provides two delayed signals from ionization and Cherenkov light. In solid-state double beta decay emitters, because of their higher density, the considered process is out of energy range. An alternative solution could be the development of double decay emitters with lower density by using for instance the aerogel technique. It is surprising that a technology used for particle identification in high-energy physics becomes a powerful tool for rejecting backgrounds in such low-energy experiments.
Ioannis Giomataris
Delayed Nickel Decay in Gamma Ray Bursts
Recently observed emission lines in the X-ray afterglow of gamma ray bursts suggest that iron group elements are either produced in the gamma ray burst, or are present nearby. If this material is the product of a thermonuclear burn, then such material would be expected to be rich in Nickel-56. If the nickel remains partially ionized, this prevents the electron capture reaction normally associated with the decay of Nickel-56, dramatically increasing the decay timescale. Here we examine the consequences of rapid ejection of a fraction of a solar mass of iron group material from the center of a collapsar/hypernova. The exact rate of decay then depends on the details of the ionization and therefore the ejection process. Future observations of iron, nickel and cobalt lines can be used to diagnose the origin of these elements and to better understand the astrophysical site of gamma ray bursts. In this model, the X-ray lines of these iron-group elements could be detected in suspected hypernovae that did not produce an observable gamma ray burst due to beaming.
G. C. McLaughlin; R. A. M. J. Wijers
D meson hadronic decays at CLEO-c
The recent CLEO-c results on hadronic decays of D and D{sub s} mesons are presented. First the absolute branching fractions for D and D{sub s} mesons using a double tag technique are discussed, then are the Cabibbo suppressed decays and doubly Cabibbo suppressed decays. Finally, I present the inclusive and rare decay modes and other measurements from CLEO-c. These decays illuminate a wide range of physics. A brief theoretical introduction is given before the corresponding discussion on measurement.
Yang, Fan; /Fermilab
Suppression of Exponential Electronic Decay in a Charged Environment
Inner-shell ionization of atoms and molecules leads to the creation of highly excited ionic states that often decay by electron emission. The dynamics of the decay is usually assumed to be exponential and the process is characterized by a decay rate. Here we show that in a multiply ionized cluster created by interaction with a high-intensity free-electron laser (FEL) radiation, trapping of the emitted electron by the neighboring ions changes the character of the decay dynamics qualitatively to the extent that it can become oscillatory instead of exponential. Implications of the predicted effect on Coster-Kronig and interatomic Coulombic decay processes induced by FELs are investigated.
Averbukh, Vitali [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Saalmann, Ulf; Rost, Jan Michael [Max Planck Institute for the Physics of Complex Systems, Noethnitzer Strasse 38, D-01187 Dresden (Germany); Max Planck Advanced Study Group at the Center for Free-Electron Laser Science, Luruper Chaussee 149, 22761 Hamburg (Germany)
The Particle Adventure | Particle decays and annihiliations | Neutron beta
Particle decays and annihiliations > Neutron beta Particle decays and annihiliations > Neutron beta decays Neutron beta decays A neutron (udd) decays to a proton (uud), an electron, and an antineutrino. This is called neutron beta decay. (The term beta ray was used for electrons in nuclear decays because they didn't know they were electrons!) Frame 1: The neutron (charge = 0) made of up, down, down quarks. Frame 2: One of the down quarks is transformed into an up quark. Since the down quark has a charge of -1/3 and and the up quark has a charge of 2/3, it follows that this process is mediated by a virtual W- particle, which carries away a (-1) charge (thus charge is conserved!) Frame 3: The new up quark rebounds away from the emitted W-. The neutron now has become a proton. Frame 4: An electron and antineutrino emerge from the virtual W- boson.
A Sterile Neutrino Search with Kaon Decay-at-rest
Monoenergetic muon neutrinos (235.5 MeV) from positive kaon decay-at-rest are considered as a source for an electron neutrino appearance search. In combination with a liquid argon time projection chamber based detector, such a source could provide discovery-level sensitivity to the neutrino oscillation parameter space indicative of a sterile neutrino. Current and future intense >3 GeV kinetic energy proton facilities around the world can be employed for this experimental concept.
J. Spitz
Search for Charged Higgs Boson Decays of the Top Quark Using Hadronic tau Decays
We present the result of a search for charged Higgs boson decays of the top quark, produced in p{bar p} collisions at {radical}s = 1.8 TeV. When the charged Higgs boson is heavy and decays to a {tau} lepton, which subsequently decays hadronically, the resulting events have a unique signature: large missing transverse energy and the low-charged-multiplicity {tau}. Data collected in 1992 and 1993 at the Collider Detector at Fermilab, corresponding to 18.7 {+-} 0.7 pb{sup -1}, exclude new regions of combined top quark and charged Higgs boson mass, in extensions to the standard model with two Higgs doublets.
Abe, F.
Engineering aspects of disruption current decay
Engineering features associated with the configuration of a tokamak can affect the amount of energy that produces melting and damage to the limiters or internal wall surfaces as the result of a major disruption. During the current decay period of a major thermal disruption, the energy that can damage a wall or limiter comes from the external magnetic field. By providing a good conducting torus near the plasma and increasing the plasma circuit resistance, this magnetic energy (transferred by way of the plasma circuit) can be minimized. This report addresses engineering design features to reduce the energy deposited on the inner torus surface that produces melting of the structures.
Murray, J.G.
Looking for meson molecules in B decays
We use the QCD sum rule approach to study a {eta} Prime - {pi} molecular current. We consider an isovector-scalar I{sup G}J{sup PC} = 1{sup -}0{sup ++} molecular current. We work at leading order in {alpha}{sub s} and consider the contributions of condensates up to dimension six. We obtain a mass around 1.1 GeV, consistent with a loosely bound state. We discuss the possibility of observing this molecular state in a B threebody hadronic decay.
Nielsen, Marina; Navarra, Fernando S. [Instituto de Fisica, Universidade de Sao Paulo, C.P. 66318, 05389-970 Sao Paulo, SP (Brazil); Bediaga, Ignacio [Centro Brasileiro de Pesquisas Fisicas, Rua Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ (Brazil)
Measurement of $D^0-overline{D}^0$ mixing parameters using $D^0 \\to K_S^0 \\pi^ \\pi^-$ and $D^0 \\to K_S^0 K^ K^-$ decays
We report a direct measurement of D{sup 0}-{bar D}{sup 0} mixing parameters through a time-dependent amplitude analysis of the Dalitz plots of D{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} and, for the first time, D{sup 0} {yields} K{sub S}{sup 0}K{sup +}K{sup -} decays. The low-momentum pion {pi}{sub s}{sup +} in the decay D*{sup +} {yields} D{sup 0}{pi}{sub s}{sup +} identifies the flavor of the neutral D meson at its production. Using 468.5 fb{sup -1} of e{sup +}e{sup -} colliding-beam data recorded near {radical}s = 10.6 GeV by the BABAR detector at the PEP-II asymmetric-energy collider at SLAC, we measure the mixing parameters x = [1.6 {+-} 2.3 (stat.) {+-} 1.2 (syst.) {+-} 0.8 (model)] x 10{sup -3}, and y = [5.7 {+-} 2.0 (stat.) {+-} 1.3 (syst.) {+-} 0.7 (model)] x 10{sup -3}. These results provide the best measurement to date of x and y. The knowledge of the value of x, in particular, is crucial for understanding the origin of mixing.
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Columbus Supercond., Genova /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Banca di Roma /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison
Sensitivity of CUORE to Neutrinoless Double-Beta Decay
In this paper, we study the sensitivity of CUORE, a bolometric double-beta decay experiment under construction at the Laboratori Nazionali del Gran Sasso in Italy. Two approaches to the computation of experimental sensitivity are discussed and compared, and the formulas and parameters used in the sensitivity estimates are provided. Assuming a background rate of 10{sup -2} cts/(keV kg y), we find that, after 5 years of live time, CUORE will have a 1#27;{sigma} sensitivity to the neutrinoless double-beta decay half-life of {caret T{sup 0{nu}}{sub 1/2}}(1{sigma}#27;) = 1.6x#2;10{sup 26} y and thus a potential to probe the effective Majorana neutrino mass down to 41-95 meV; the sensitivity at 1.64{sigma}#27;, which corresponds to 90% C.L., will be {caret T{sup 0{nu}}{sub 1/2}(1.64{sigma}#27;}) = 9.5x10{sup 25} y. This range is compared with the claim of observation of neutrinoless double-beta decay in {sup 76}Ge and the preferred range in the neutrino mass parameter space from oscillation results.
CUORE; Alessandria, F.; Andreotti, E.; Ardito, R.; Arnaboldi, C.; Avignone III, F. T.; Balata, M.; Bandac, I.; Banks, T. I.; Bari, G.; Beeman, J.; Bellini, F.; Bersani, A.; Biassoni, M.; Bloxham, T.; Brofferio, C.; Bryant, A.; Bucci, C.; Cai, X. Z.; Canonica, L.; Capelli, S.; Carbone, L.; Cardani, L.; Carrettoni, M.; Casali, N.; Chott, N.; Clemenza, M.; Cosmelli, C.; Cremonesi, O.; Creswick, R. J.; Dafinei, I.; Dally, A.; Biasi, A. De; Decowski, M. P.; Deninno, M. M.; Waard, A. de; Domizio, S. Di; Ejzak, L.; Faccini, R.; Fang, D. Q.; Farach, H. A.; Ferri, E.; Ferroni, F.; Fiorini, E.; Foggetta, L.; Franceschi, M. A.; Freedman, S. J.; Frossati, G.; Fujikawa, B. K.; Giachero, A.; Gironi, L.; Giuliani, A.; Gorla, P.; Gotti, C.; Guardincerri, E.; Gutierrez, T. D.; Haller, E. E.; Han, K.; Heeger, K. M.; Huang, H. Z.; Ichimura, K.; Kadel, R.; Kazkaz, K.; Keppel, G.; Kogler, L.; Kolomensky, Yu. G.; Kraft, S.; Lenz, D.; Li, Y. L.; Liu, X.; Longo, E.; Ma, Y. G.; Maiano, C.; Maier, G.; Maino, M.; Mancini, C.; Martinez, C.; Martinez, M.; Maruyama, R. H.; Moggi, N.; Morganti, S.; Napolitano, T.; Newman, S.; Nisi, S.; Nones, C.; Norman, E. B.; Nucciotti, A.; Orio, F.; Orlandi, D.; Ouellet, J. L.; Pallavicini, M.; Palmieri, V.; Pattavina, L.; Pavan, M.; Pedretti, M.; Pessina, G.; Pirro, S.; Previtali, E.; Rampazzo, V.; Rimondi, F.; Rosenfeld, C.; Rusconi, C.; Salvioni, C.; Sangiorgio, S.; Schaeffer, D.; Scielzo, N. D.; Sisti, M.; Smith, A. R.; Stivanello, F.; Taffarello, L.; Terenziani, G.; Tian, W. D.; Tomei, C.; Trentalange, S.; Ventura, G.; Vignati, M.; Wang, B. S.; Wang, H. W.; Whitten Jr., C. A.; Wise, T.; Woodcraft, A.; Xu, N.; Zanotti, L.; Zarra, C.; Zhu, B. X.; Zucchelli, S.
Reduced Beta Decay Rates of Iron Isotopes for Supernova Physics
During the late phases of stellar evolution beta decay on iron isotopes, in the core of massive stars, plays a crucial role in the dynamics of core-collapse. The beta decay contributes in maintaining a 'respectable' lepton-to-baryon ratio (PSI{sub e}) of the core prior to collapse which results in a larger shock energy to power the explosion. It is indeed a fine tuning of the parameter PSI{sub e} at various stages of supernova physics which can lead to a successful transformation of the collapse into an explosion. The calculations presented here might help in fine-tuning of PSI{sub e} for the collapse simulators of massive stars.
Nabi, Jameel-Un [Faculty of Engineering Sciences, GIK Institute of Engineering Sciences and Technology, Topi 23460, N.W.F.P. (Pakistan)
Decaying Higgs Fields and Cosmological Dark Energy
The observed dark energy in the universe might give particles inertial mass. We investigate one realization of this idea, that the dark energy field might be a decayed scalar component of a supermultiplet field in the early universe that creates inertial mass through spontaneous symmetry breaking, e.g. a Higgs field. To investigate this possibility, the cosmological Friedmann equation of energy balance is augmented in a standard way to incorporate a minimally coupled cosmological Higgs. For epochs where the expansion of the universe is driven by matter and radiation and not the scalar field, the observed hidden nature of the Higgs field can be codified into a single differential equation that we call the "hidden higgs" condition. The resulting differential equation is solved for the time dependant scalar field and a simple and interesting solution is found analytically. Such a Higgs field decays from Planck scale energies rapidly and approximately exponentially from onset, leaving only the initially negligible constant term of the potential as a final cosmological constant. Such evolution replaces the hierarchy problem with the problem of explaining why such evolution is physically justified.
Robert J. Nemiroff; Bijunath Patla
Proton decay matrix elements on the lattice
Hadronic matrix elements of proton decay are essential ingredients to bridge the grand unification theory to low energy observables like proton lifetime. In this paper we non-perturbatively calculate the matrix elements, relevant for the process of a nucleon decaying into a pseudoscalar meson and an anti-lepton through generic baryon number violating four-fermi operators. Lattice QCD with 2+1 flavor dynamical domain-wall fermions with the {\\it direct} method, which is direct measurement of matrix element from three-point function without chiral perturbation theory, are used for this study to have good control over the lattice discretization error, operator renormalization, and chiral extrapolation. The relevant form factors for possible transition process from an initial proton or neutron to a final pion or kaon induced by all types of three quark operators are obtained through three-point functions of (nucleon)-(three-quark operator)-(meson) with physical kinematics. In this study all the relevant systematic uncertainties of the form factors are taken into account for the first time, and the total error is found to be the range 30%-40% for $\\pi$ and 20%-40% for $K$ final states.
Y. Aoki; E. Shintani; A. Soni
Theoretical Review on CP Violation in Rare B decays
We discuss several issues related to direct CP violation in rare $B$ meson decays. We review the use of CP asymmetries in extracting information of strong and weak phases, how the experimental data fit into the overall picture, and the current status of the $K \\pi$ puzzle. We also examine the flavor symmetry assumption using closely related decay modes and extract the weak phase $\\gamma$ from certain $B \\to K^* \\pi$ and $\\rho K$ decays.
Chiang, Cheng-Wei
Cheng-Wei Chiang
Study of the decay $\\Lambda$sub(c) --> $\\Lambda$ l$^{+}$ $\
Using the CLEO II detector at CESR, we observe 500 \\Lambda l^+ pairs consistent with the semileptonic decay \\Lambda_c \\to \\Lambda l^+ \
Bergfeld, T; Gollin, G; Ong, B; Palmer, M; Selen, M; Thaler, J J; Sadoff, A J; Ammar, R; Ball, S; Baringer, P; Bean, A; Besson, D; Coppage, D; Copty, N; Davis, R; Hancock, N; Kelly, M; Kwak, N; Lam, H; Kubota, Y; Lattery, M; Nelson, J K; Patton, S; Perticone, D; Poling, R; Savinov, V; Schrenk, S; Wang, R; Alam, M S; Kim, I J; Nemati, B; O'Neill, J J; Severini, H; Sun, C R; Zoeller, M M; Crawford, G; Daubenmier, C M; Fulton, R; Fujino, D; Gan, K K; Honscheid, K; Kagan, H; Kass, R; Lee, J; Malchow, R; Morrow, F; Skovpen, Y; Sung, M; White, C; Butler, F; Fu, X; Kalbfleisch, G; Ross, W R; Skubic, P L; Snow, J; Wang, P L; Wood, M; Brown, D N; Fast, J; McIlwain, R L; Miao, T; Miller, D H; Modesitt, M; Payne, D; Shibata, E I; Shipsey, I P J; Wang, P N; Battle, M; Ernst, J; Kwon, Y; Roberts, S; Thorndike, E H; Wang, C H; Dominick, J; Lambrecht, M; Sanghera, S; Shelkov, V; Skwarnicki, T; Stroynowski, R; Volobuev, I P; Wei, G; Zadorozhny, P; Artuso, M; Goldberg, M; He, D; Horwitz, N; Kennett, R; Mountain, R; Moneti, G C; Muheim, F; Mukhin, Y; Playfer, S; Rozen, Y; Stone, S; Thulasidas, M; Vasseur, G; Zhu, G; Bartelt, J; Csorna, S E; Egyed, Z; Jain, V; Kinoshita, K; Edwards, K W; Ogg, M; Britton, D I; Hyatt, E R F; MacFarlane, D B; Patel, P M; Akerib, D S; Barish, B; Chadha, M; Chan, S; Cowen, D F; Eigen, G; Miller, J S; O'Grady, C; Urheim, J; Weinstein, A J; Acosta, D; Athanas, M; Masek, G; Paar, H P; Gronberg, J; Kutschke, R; Menary, S; Morrison, R J; Nakanishi, S; Nelson, H N; Nelson, T K; Qiao, C; Richman, J D; Ryd, A; Tajima, H; Schmidt, D; Sperka, D; Witherell, M S; Procario, M; Balest, R; Cho, K; Daoudi, M; Ford, W T; Johnson, D R; Lingel, K; Lohner, M; Rankin, P; Smith, J G; Alexander, J P; Bebek, C; Berkelman, K; Bloom, K; Browder, T E; Cassel, D G; Cho, H A; Coffman, D M; Drell, P S; Ehrlich, R; Garc�a-Sciveres, M; Geiser, B; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Jones, C D; Jones, S L; Kandaswamy, J; Katayama, N; Kim, P C; Kreinick, D L; Ludwig, G S; Masui, J; Mevissen, J; Mistry, N B; Ng, C R; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Salman, S; Sapper, M; W�rthwein, F; Avery, P; Freyberger, A; Rodr�guez, J; Stephens, R; Yang, S; Yelton, J; Cinabro, D; Henderson, S; Liu, T; Saulnier, M; Wilson, R; Yamamoto, H
Searches for Leptonic B Decays at BaBar
Measurements of the branching fractions of purely leptonic decays of B-mesons translate into constraints in the plane of the charged Higgs mass versus tan {beta} which are relatively insensitive to the particular theoretical model. Using the full BABAR dataset of 450 million B-decays we search for these decays. No significant signal is found in the decays into electrons or muons and we set upper limits on the branching fractions of the order of a 10{sup -6} at 90% confidence level. We measure the branching fraction of B {yields} {tau}{mu} to be (1.7 {+-} 0.6) x 10{sup -4}.
Nelson, Silke; /SLAC
Physicists Challenge Reports of Accelerated Decay of Nuclear...
Photon Source at Argonne, appear in the August 13 edition of Physical Review Letters. Nuclear isomers include excited states of nuclei that electromagnetically decay slowly...
Radioactive-nuclide decay data in science and technology
The scope of ENDF/B has recently been expanded to include radioactive- nuclide decay data. In this paper, the content and organization of the decay data which are included in ENDF/B are presented and discussed. The application of decay data in a wide variety of nuclear-related activities is illustrated by a number of examples. Two items pointed up by the ENDF/B decay-data compilation effort are treated: the identification of deficiencies in the data; and the importance of a radioactive-nuclide metrology effort oriented toward supplying these needs in a systematic fashion. (3 figures, 1 table) (auth)
Reich, C.W.; Helmer, R.G.
Decay processes in an inhomogeneous time-varying plasma
The decay of a homogeneous pump field in an inhomogeneous time-varying plasma into a plasma wave and an ion-acoustic wave is considered theoretically.
Andreev, A.A.; Fedorov, V.I.
Optical detection of atmospheric 238U decay products
Current and proposed programs involving aerial survey of uranium resources require remote sensing of 238U decay products with high sensitivity. In this paper
Jerry E. Solomon
Decays of J/psi (3100) to baryon final states
We present results for the decays of psi(3100) into baryon and hyperon final states. The sample studied here consists of 1.3 million produced psi decays. The decays into nonstrange baryons agree well with currently established results, but with better statistics. In addition, significant resonance formation in multibody final states is observed. The decay psi ..-->.. anti pp..gamma.., the first direct photon decay of the psi involving baryons in the final state, is presented and the theoretical implications of the decays are briefly explored. Several new decays of the psi involving strange baryons are explored, including the first observations of three body final states involving hyperons. The I-spin symmetry of the strong decay psi ..-->.. baryons has clearly been observed. The reduced matrix elements for psi ..-->.. B anti B are presented for final states of different SU(3) content. The B/sub 8/ anti B/sub 8/ results are in excellent agreement with the psi being an SU(3) singlet as are the results for psi ..-->.. B/sub 10/ anti B/sub 10/. We present the first evidence for the SU(3) violating decays of the type psi ..-->.. B/sub 8/ anti B/sub 10/ + c.c.. Angular distributions for psi ..-->.. B/sub 8/ anti B/sub 8/ are presented and compared with theoretical predictions. Statistics are limited, but the data tends to prefer other than a 1 + Cos/sup 2/theta distribution.
Eaton, M.W.
CP violation in three-body chargino decays
CP violation in supersymmetry can give rise to rate asymmetries in the decays of supersymmetric particles. In this work we compute the rate asymmetries for the three-body chargino decays {chi}-tilde{sub 2}{sup {+-}}{yields}{chi}-tilde{sub 1}{sup {+-}}HH, {chi}-tilde{sub 2}{sup {+-}}{yields}{chi}-tilde{sub 1}{sup {+-}}ZZ, {chi}-tilde{sub 2}{sup {+-}}{yields}{chi}-tilde{sub 1}{sup {+-}}W{sup +}W{sup -} and {chi}-tilde{sub 2}{sup {+-}}{yields}{chi}-tilde{sub 1}{sup {+-}}ZH. Each of the decays contains contributions mediated by neutral Higgs bosons that can possibly go on shell. Such contributions receive a resonant enhancement; furthermore, the strong phases required for the CP asymmetries come from the widths of the exchanged Higgs bosons. Our results indicate that the rate asymmetries can be relatively large in some cases, while still respecting a number of important low-energy bounds such as those coming from B meson observables and electric dipole moments. For the parameters that we consider, rate asymmetries of order 10% are possible in some cases.
Nagashima, Makiko; Szynkman, Alejandro; London, David [Physique des Particules, Universite de Montreal, C.P. 6128, succursale centre-ville, Montreal, QC, Canada H3C 3J7 (Canada); Kiers, Ken; Hanchey, Jenna; Little, Kevin [Physics and Engineering Department, Taylor University, 236 West Reade Avenue, Upland, Indiana 46989 (United States)
Search for invisibly decaying Higgs bosons
In the last running years, the four Large Electron Positron collider (LEP) experiments collected a combined luminosity of almost 2.5 fb ?1 at ? s ? 189 GeV. This data was searched for invisibly decaying Higgs bosons produced in association with a Z boson. The channels with electrons, muons and hadrons were investigated. None of the experiments sees hints for the production of such an invisible Higgs boson, thus each of them sets an individual lower limit on the mass at 95 % confidence level. The highest of the four limits is set at 114.1 GeV. The combination of the final results has yet to be done and will increase the reach of the search. PoS(HEP2005)329
Andr� Georg Holzner; Andr� Georg Holzner
Chiral Suppression of Scalar Glueball Decay
Because glueballs are SU(3){sub Flavor} singlets, they are expected to couple equally to u,d, and s quarks, so that equal coupling strengths to {pi}{sup +}{pi}{sup -} and K{sup +}K{sup -} are predicted. However, we show that chiral symmetry implies the scalar glueball amplitude for G{sub 0} {yields} {bar q}q is proportional to the quark mass, so that mixing with {bar s}s mesons is enhanced and decays to K{sup +}K{sup -} are favored over {pi}{sup +}{pi}{sup -}. Together with evidence from lattice calculations and from experiment, this supports the hypothesis that f{sub 0}(1710) is the ground state scalar glueball.
Chanowitz, Michael S.
Distribution of ranks of ?-decay half-lives
I studied the distribution of ranks of values of 2949 {\\beta}-decay half-lives according to an empirical beta law with two exponents. {\\beta}-decay half-life ranks showed good fit to a beta function with two exponents.
Juan Miguel Campanario
Reach in All Hadronic Stop Decays: A Snowmass White Paper
We study the discovery prospects for stops which decay to a top and a light neutralino. We consider fully hadronic decays of the tops and present an estimate for the reach at various future collider runs. Our results are summarized in Table 1.
Stolarski, Daniel
On the Decay of Tropical Cyclone Winds Crossing Narrow Landmasses
A method is developed to adjust the Kaplan and DeMaria tropical cyclone inland wind decay model for storms that move over narrow landmasses. The basic assumption that the wind speed decay rate after landfall is proportional to the wind speed is ...
Mark DeMaria; John A. Knaff; John Kaplan
Daniel Stolarski
Baryonic Decays of Charmonium - a Window on Internal Baryon Structure
The baryonic decays of $J/ \\psi$ provide a new way to study the internal structure of baryons. A simple diquark model applied to the calculation of the $\\bar{B}B$ decay cross-sections is compared with the ordinary constituent quark model. Various models also give different predictions for the rates involving the $N^{\\ast}(1440)$ resonance in the final state.
A. Cieply
Pure annihilation type $ D\\to PP(V)$ decays in the perturbative QCD approach
The annihilation type diagrams are difficult to calculate in any kind of models or method. Encouraged by the the successful calculation of pure annihilation type B decays in the perturbative QCD factorization approach, we calculate the pure annihilation type $D\\to PP(V)$ decays in the perturbative QCD approach based on the $k_T$ factorization. Although the expansion parameter $1/m_D$ is not very small, our leading order numerical results agree with the existing experiment data for most channels. We expect the more accurate observation from experiments, which can help us learn about the dynamics of $D$ meson weak decays.
Zhi-Tian Zou; Cheng Li; Cai-Dian L�
Alpha-nucleus potential for alpha-decay and sub-barrier fusion
The set of parameters for alpha-nucleus potential is derived by using the data for both the alpha-decay half-lives and the fusion cross-sections around the barrier for reactions alpha+40Ca, alpha+59Co, alpha+208Pb. The alpha-decay half-lives are obtained in the framework of a cluster model using the WKB approximation. The evaluated alpha-decay half-lives and the fusion cross-sections agreed well with the data. Fusion reactions between alpha-particle and heavy nuclei can be used for both the formation of very heavy nuclei and spectroscopic studies of the formed compound nuclei.
V. Yu. Denisov; H. Ikezoe
CP violation in strange baryon decays: A report from Fermilab experiment 871
Fermilab experiment 871, HyperCP, is a search for direct CP violation in {xi} and {lambda} hyperon decays. A non-zero value in the asymmetry parameter A, defined in terms of the decay parameter products {alpha}{sub {xi}}{alpha}{sub {lambda}} and {alpha}{sub {xi}}-bar{alpha}{sub {lambda}}-bar, would be unambiguous evidence for direct CP violation. The first data-taking run finished at the end of 1997 and accumulated over one billion {xi}{sup -} and {xi}-bar{sup +} decays. A sensitivity in A of {approx_equal}10{sup -4} is expected. A review of CP violation in hyperon decays is given, the HyperCP detector is described, and the status of the data analysis is discussed.
James, C.; Volk, J. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Burnstein, R. A.; Chakravorty, A.; Kaplan, D. M.; Lederman, L. M.; Luebke, W.; Rajaram, D.; Rubin, H. A.; White, C. G.; White, S. L. [Illinois Institute of Technology, Chicago, Illinois 60616 (United States); Chan, A.; Chen, Y. C.; Ho, C.; Teng, P. K. [Academia Sinica, Nankang, Taipei 11529, Taiwan (China); Choong, W. S.; Fuzesy, R.; Gidal, G.; Luk, K. B.; Turko, B. [University of California and Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States)] (and others)
Measurements of Time-Dependent CP-Asymmetry Parameters in B Meson Decays to \\eta^{\\prime} K^0 and of Branching Fractions of SU(3) Related Modes with BaBar Experiment at SLAC
In this thesis work we have measured the following upper limits at 90% of confidence level, for B meson decays (in units of 10{sup -6}), using a statistics of 465.0 x 10{sup 6} B{bar B} pairs: {Beta}(B{sup 0} {yields} {eta}K{sup 0}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{eta}) < 1.4 {Beta}(B{sup 0} {yields} {eta}{prime}{eta}{prime}) < 2.1 {Beta}(B{sup 0} {yields} {eta}{phi}) < 0.52 {Beta}(B{sup 0} {yields} {eta}{omega}) < 1.6 {Beta}(B{sup 0} {yields} {eta}{prime}{phi}) < 1.2 {Beta}(B{sup 0} {yields} {eta}{prime}{omega}) < 1.7 We have no observation of any decay mode, statistical significance for our measurements is in the range 1.3-3.5 standard deviation. We have a 3.5{sigma} evidence for B {yields} {eta}{omega} and a 3.1 {sigma} evidence for B {yields} {eta}{prime}{omega}. The absence of observation of the B{sup 0} {yields} {eta}K{sup 0} open an issue related to the large difference compared to the charged mode B{sup +} {yields} {eta}K{sup +} branching fraction, which is measured to be 3.7 {+-} 0.4 {+-} 0.1 [118]. Our results represent substantial improvements of the previous ones [109, 110, 111] and are consistent with theoretical predictions. All these results were presented at Flavor Physics and CP Violation (FPCP) 2008 Conference, that took place in Taipei, Taiwan. They will be soon included into a paper to be submitted to Physical Review D. For time-dependent analysis, we have reconstructed 1820 {+-} 48 flavor-tagged B{sup 0} {yields} {eta}{prime}K{sup 0} events, using the final BABAR statistic of 467.4 x 10{sup 6} B{bar B} pairs. We use these events to measure the time-dependent asymmetry parameters S and C. We find S = 0.59 {+-} 0.08 {+-} 0.02, and C = -0.06 {+-} 0.06 {+-} 0.02. A non-zero value of C would represent a directly CP non-conserving component in B{sup 0} {yields} {eta}{prime}K{sup 0}, while S would be equal to sin2{beta} measured in B{sup 0} {yields} J/{psi}K{sub s}{sup 0} [108], a mixing-decay interference effect, provided the decay is dominated by amplitudes of a single weak phase. The new measured value of S can be considered in agreement with the expectations of the 'Standard Model', inside the experimental and theoretical uncertainties. Inconsistency of our result for S with CP conservation (S = 0) has a significance of 7.1 standard deviations (statistical and systematics included). Our result for the direct-CP violation parameter C is 0.9 standard deviations from zero (statistical and systematics included). Our results are in agreement with the previous ones [18]. Despite the statistics is only 20% larger than the one used in previous measurement, we improved of 20% the error on S and of 14% the error on C. This error is the smaller ever achieved, by both BABAR and Belle, in Time-Dependent CP Violation Parameters measurement is a b {yields} s transition.
Biassoni, Pietro; /Milan U.
Search for di-muon decays of a low-mass Higgs boson in radiative decays of the ?(1S)
We search for di-muon decays of a low-mass Higgs boson (A[superscript 0]) produced in radiative ?(1S) decays. The ?(1S) sample is selected by tagging the pion pair in the ?(2S,3S)??[superscript +]?[superscript -]?(1S) ...
Neutrinos from Decaying Muons, Pions, Kaons and Neutrons in Gamma Ray Bursts
In the internal shock model of gamma ray bursts ultrahigh energy muons, pions, neutrons and kaons are likely to be produced in the interactions of shock accelerated relativistic protons with low energy photons (KeV-MeV). These particles subsequently decay to high energy neutrinos/antineutrinos and other secondaries. In the high internal magnetic fields of gamma ray bursts, the ultrahigh energy charged particles ($\\mu^+$, $\\pi^+$, $K^+$) lose energy significantly due to synchrotron radiations before decaying into secondary high energy neutrinos and antineutrinos. The relativistic neutrons decay to high energy antineutrinos, protons and electrons. We have calculated the total neutrino flux (neutrino and antineutrino) considering the decay channels of ultrahigh energy muons, pions, neutrons and kaons. We have shown that the total neutrino flux generated in neutron decay can be higher than that produced in $\\mu^+$ and $\\pi^+$ decay. The charged kaons being heavier than pions, lose energy slowly and their secondary total neutrino flux is more than that from muons and pions at very high energy. Our detailed calculations on secondary particle production in $p\\gamma$ interactions give the total neutrino fluxes and their flavour ratios expected on earth. Depending on the values of the parameters (luminosity, Lorentz factor, variability time, spectral indices and break energy in the photon spectrum) of a gamma ray burst the contributions to the total neutrino flux from the decay of different particles (muon, pion, neutron and kaon) may vary and they would also be reflected on the neutrino flavour ratios.
Reetanjali Moharana; Nayantara Gupta
Extracellular oxidative metabolism of wood decay fungi
Substantial progress has been made toward understanding the fundamental physiology and genetics of wood decay fungi, microbes that are capable of degrading all major components of plant cell walls. Efficient utilization of lignocellulosic biomass has been hampered in part by limitations in our understanding of enzymatic mechanisms of plant cell wall degradation. This is particularly true of woody substrates where accessibility and high lignin content substantially complicate enzymatic 'deconstruction'. The interdisciplinary research has illuminated enzymatic mechanisms essential for the conversion of lignocellulosics to simple carbohydrates and other small molecular weight products. Progress was in large part dependent on substantial collaborations with the Department of Energy's Joint Genome Institute (JGI) in Walnut Creek and Los Alamos, as well as the Catholic University, Santiago, Chile, the Royal Institute of Technology, Stockholm, the University of Minnesota, St. Paul, and colleagues at the University of Wisconsin and the Forest Products Laboratory. Early accomplishments focused on the development of experimental tools (2, 7, 22, 24-26, 32) and characterization of individual genes and enzymes (1, 3-5, 8, 9, 11, 14, 15, 17, 18, 23, 27, 33). In 2004, the genome of the most intensively studied lignin-degrading fungus, Phanerochaete chrysosporium, was published (21). This milestone lead to additional progress on this important model system (6, 10, 12, 13, 16, 28-31) and was further complemented by genome analysis of other important cellulose-degrading fungi (19, 20). These accomplishments have been highly cited and have paved the way for whole new research areas.
Daniel Cullen
Searches for New Physics in Top Decays at D0
The Tevatron proton-antiproton collider at Fermilab with its centre of mass energy of 1.96 TeV allows for pair production of top quarks and the study of top quark decay properties. This report reflects the current status of measurements of the W boson helicity in top quark decays and the ratio of top quark branching fractions as well as searches for neutral current top quark decays and pair production of fourth generation t' quarks, performed by the D0 Collaboration utilising datasets of up to 5.4 fb{sup -1}.
Pleier, Marc-Andre; /Brookhaven
Update analysis of two-body charmed $B$ meson decays
The charmed B decays, $B\\to DP, ~D^*P$ and $DV$, are re-analyzed using the latest experimental data, where $P$ and $V$ denote the pseudoscalar meson and vector meson, respectively. We perform global fits under the assumption of flavor SU(3) symmetry. The size of the decay amplitudes and the strong phases between the topologically distinct amplitudes are studied. Predictions of the related $B_s$ decay rates are made based upon the fitted results. We also note a serious SU(3) symmetry breaking or inconsistency in the $DV$ sector.
Chiang, C W; Chiang, Cheng-Wei; Senaha, Eibun
Recent experimental results on nonleptonic hyperon decays are studied on the basis of a doublet approximation for strong and weak interactions, with the implied suggestion that this higher symmetry may be more easlly discernable in such reactions in which K-panticles do not occur explicitly. The doublet approximation is characterized by a doublet spin I which is equal to 1/2, 1, 0 for baryons, pi , K, respectively, and by a K spin. It is not necessary to assume that the strong K interactions are weak compared to the strong pi interactions. For the mentioned reactions it is necessary to assume that the strong interactions which do not conserve I play a minor role compared to those which conserve I. The following refinement of the nonleptonic DELTA T = 1/2 rule is proposed. (T = isotopic spin.) The weak nonleptonic interactions consist of two parts H/sup (0)/, H/sup (1)/ with DELTA I = 0, 1, respectively. In the doublet approximation H/sup (o)/ and H/sup (1)/ separately conserve parity in the presence of all strong pi and K interactions. H/sup (o)/ and H/sup (1)/ together do not conserve parity, however. In addition to DELTA I = 1, H/sup )1)/ should in general satisfy a further constraint, but there are classes of graphs for which DELTA I = 1 is sufficient. Current x current structures for H/sup (o)/ and H/sup (1)/ are examined. Resul ts of an earlier paper can be viewed as a special case of the DELTA I = 0, 1 rule. The same is true for results obtained by Feldman, Matthews, and Salam and by Woifenstein. The considerations of these authors can be extended to wider classes of graphs. Odd relative helicity and the relation between rates for LAMBDA -- p + pi -, SIGMA + -- p + pi /sup o/ are consequences of the DELTA I = 0, 1 rule only. So is the prediction that XI decay is strongly P nonconserving. The parity properties of H/sup (o)/ H/sup (1)/ are sufficient conditions. It is a delicate question whether they are necessary. For a subset of graphs they are not necessary, but this set seems arbitrary. If it is assumed that the parity conditions are necessary, the schizon scheme is ruled out. It is noted that the nonleptonic weak interactions may be generated by the strong interactions in terms of the following prescription. H/sup (1)/ is generated by assuming that the pi (K) fields have small K( pi ) components. An H/sup (o)/ is generated by assuming that the doublets N/sup 1/(N/sup 2/) have small N/sub 2/(N/sub 1/) components; likewise for N/sub 3/ and N/sub 4/. Further, it is observed thai one can construct a non- electromagnetic DELTA T =3/2 interaction which is small in the sense that it only contributes to K/sub pi //sub 2+/ to the extent t hat the doublet approximation is not valid. (auth)
Pais, A.
A Toy Model Study of Decay Trapping | Superconducting Magnet Division
A Toy Model Study of Decay Trapping, reported by Brett Parker A Toy Model Study of Decay Trapping, reported by Brett Parker Introduction A group from the BNL Superconducting Magnet Division is looking at various options for dipole magnets which would be suitable for use in a muon storage ring that is used as a neutrino factory. Since the useful neutrino beams from a neutrino factory come from straight sections it is desirable to minimize the rings arc circumference, in relation to straight section length, in order to ensure that the fraction of muons which decay in the straight section is as large as possible. Therefore superconducting magnets, with higher B-fields and smaller bend radii, are reasonable to consider for this application. Unfortunately the decay electrons generated along with the neutrinos carry on average about a third of the original
Renewal convergence rates and correlation decay for homogeneous pinning models
A class of discrete renewal processes with super-exponentially decaying inter-arrival distributions coincides with the infinite volume limit of general homogeneous pinning models in their localized phase. Pinning models are statistical mechanics systems to which a lot of attention has been devoted both for their relevance for applications and because they are solvable models exhibiting a non-trivial phase transition. The spatial decay of correlations in these systems is directly mapped to the speed of convergence to equilibrium for the associated renewal processes. We show that close to criticality, under general assumptions, the correlation decay rate, or the renewal convergence rate, coincides with the inter-arrival decay rate. We also show that, in general, this is false away from criticality. Under a stronger assumption on the inter-arrival distribution we establish a local limit theorem, capturing thus the sharp asymptotic behavior of correlations.
Giacomin, Giambattista
Giambattista Giacomin
Dynamics of Excimer Formation and Decay in Supercritical Krypton
Dynamics of Excimer Formation and Decay in Supercritical Krypton R. A. Holroyd, A. R. Cook and J. M. Preses J. Chem. Phys. 131, 224509 (2009). Find paper at Scitation Abstract:...
Lepton flavor violation decays with the fourth generation neutrino
We investigate the lepton flavor violation decays, $\\tau \\to \\mu\\gamma$, $\\tau \\to e\\gamma$ and $\\mu \\to e\\gamma$, in the framwork of a squential fourth generation model with a heavy fourth neutrino, $\
Huo, W J; Huo, Wu-Jun; Feng, Tai-Fu
Neutrino-less Double Beta Decay and Particle Physics
We review the particle physics aspects of neutrino-less double beta decay. This process can be mediated by light massive Majorana neutrinos (standard interpretation) or by something else (non-standard interpretations). The physics potential of both interpretations is summarized and the consequences of future measurements or improved limits on the half-life of neutrino-less double beta decay are discussed. We try to cover all proposed alternative realizations of the decay, including light sterile neutrinos, supersymmetric or left-right symmetric theories, Majorons, and other exotic possibilities. Ways to distinguish the mechanisms from one another are discussed. Experimental and nuclear physics aspects are also briefly touched, alternative processes to double beta decay are discussed, and an extensive list of references is provided.
Werner Rodejohann
Evidence of the Higgs Boson Decaying into Two Photons.
??A search for the standard model Higgs boson decaying to two photons will be presented. The analysis will cover 5.1 fb-1 and 19.6 fb-1 of� (more)
Berry, Douglas R
Decay of the Navier-Stokes-Poisson equations
We establish the time decay rates of the solution to the Cauchy problem for the compressible Navier-Stokes-Poisson system via a refined pure energy method. In particular, the optimal decay rates of the higher-order spatial derivatives of the solution are obtained. The $\\Dot{H}^{-s}$($0\\le srates. As a corollary, we also obtain the usual $L^p$--$L^2$($1rates. Compared to the compressible Navier-Stokes system and the compressible irrotational Euler-Poisson system, our results imply that both the dispersion effect of the electric field and the viscous dissipation contribute to enhance the decay rate of the density. Our proof is based on a family of scaled energy estimates with minimum derivative counts and interpolations among them without linear decay analysis.
Wang, Yanjin
Searching for Double Beta Decay with the Enriched Xenon Observatory
The Enriched Xenon Observatory (EXO) Collaboration is building a series of experiments to search for the neutrinoless double beta decay of {sup 136}Xe. The first experiment, known as EXO-200, will utilize 200 kg of xenon enriched to 80% in the isotope of interest, making it the largest double beta decay experiment to date by one order of magnitude. This experiment is rapidly being constructed, and will begin data taking in 2007. The EXO collaboration is also developing a technique to identify on an event-by-event basis the daughter barium ion of the double beta decay. If successful, this method would eliminate all conventional radioactive backgrounds to the decay, resulting in an ideal experiment. We summarize here the current status of EXO-200 construction and the barium tag R&D program.
Hall, C.; /SLAC
The �Footprint� under a Decaying Tropical Mesoscale Convective System
On 10 February 1993, during the Tropical Ocean Global Atmosphere Coupled Ocean�Atmosphere Response Experiment, the two NOAA WP-3Ds and the NCAR Electra flew under the anvil region of a decaying mesoscale convective system (MCS). Satellite and ...
Mark F. Geldmeier; Gary M. Barnes
Large-Eddy Simulation of Decaying Stably Stratified Turbulence
A large-eddy simulation (LES) model is developed and employed to study the interactions among turbulent and internal gravity wave motions in a uniformly stratified fluid at oceanic space and time scales. The decay of a random initial energy ...
David A. Siegel; J. Andrzej Domaradzki
MEASUREMENT OF yyy FINAL STATES IN y DECAY
Fig. 2. The high mass projection of these data clearly showsdominate the low mass projection. There is no evidence inline in the high mass projection of Fig. 2. decays is The
Himel, T.M.
Double Beta Decay: Historical Review of 75 Years of Research
Main achievements during 75 years of research on double beta decay have been reviewed. The existing experimental data have been presented and the capabilities of the next-generation detectors have been demonstrated.
A. S. Barabash
Modal Decay in the Australia�Antarctic Basin
The barotropic intraseasonal variability in the Australia�Antarctic Basin (AAB) is studied in terms of the excitation and decay of topographically trapped barotropic modes. The main objective is to reconcile two widely differing estimates of the ...
Wilbert Weijer; Sarah T. Gille; Fr�d�ric Vivier
$?$ meson exchange effect on nonmesonic hypernuclear weak decay observables
We analyze the influence of $\\sigma$ meson exchange on the main nonmesonic hypernuclear weak decay observables: the total rate, $\\Gamma_{NM}$, the neutron-to-proton branching ratio, $\\Gamma_{n/p}$, and the proton asymmetry parameter, $a_\\Lambda$. The $\\sigma$ meson exchange is added to the standard strangeness-changing weak $\\Lambda N\\to NN$ transition potential, which includes the exchange of the complete pseudoscalar and vector mesons octet ($\\pi$, $\\eta$, $K$, $\\rho$, $\\omega$, $K^*$). Using a shell model formalism, the $\\sigma$ meson weak coupling constants are adjusted to reproduce the recent $\\Gamma_{NM}$ and $\\Gamma_{n/p}$ experimental data for $^5_{\\Lambda}He$. Numerical results for the remaining observables of $^5_{\\Lambda}He$ and all the observables of $^{12}_{\\Lambda}C$ decays are presented. They clearly show that the addition of the $\\sigma$ meson, in spite of improving some observables values, is not enough to reproduce simultaneously all the measurements, and the puzzle posed by the experimental data remains unexplained.
C. Barbero; A. Mariano
Search for Hadronic Decays of a Light Higgs Boson in the Radiative Decay
The authors search for hadronic decays of a light Higgs boson (A{sup 0}) produced in radiative decays of an {Upsilon}(2S) or {Upsilon}(3S) meson, {Upsilon} {yields} {gamma}A{sup 0}. The data have been recorded by the BABAR experiment at the {Upsilon}(3S) and {Upsilon}(2S) center of mass energies, and include (121.3 {+-} 1.2) x 10{sup 6} {Upsilon}(3S) and (98.3 {+-} 0.9) x 10{sup 6} {Upsilon}(2S) mesons. No significant signal is observed. We set 90% confidence level upper limits on the product branching fractions {beta}({Upsilon}(nS) {yields} {gamma}A{sup 0}) {center_dot} {beta}(A{sup 0} {yields} hadrons) (n = 2 or 3) that range from 1 x 10{sup -6} for an A{sup 0} mass of 0.3 GeV/c{sup 2} to 8 x 10{sup -5} at 7 GeV/c{sup 2}.
Lees, J.P.; Poireau, V.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D.A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Koch, H.; Schroeder, T.; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.
Searching for the fourth family quarks through anomalous decays
The flavor democracy hypothesis predicts the existence of the fourth standard model family. Because of the high masses of the fourth family quarks, their anomalous decays could be dominant if certain criteria are met. This will drastically change the search strategy at hadron colliders. We show that the fourth standard model family down quarks with masses up to 400-450 GeV can be observed (or excluded) via anomalous decays by Tevatron.
Sahin, M.; Sultansoy, S.; Turkoz, S. [TOBB University of Economics and Technology, Physics Division, Ankara (Turkey); TOBB University of Economics and Technology, Physics Division, Ankara, Turkey and Institute of Physics, National Academy of Sciences, Baku (Azerbaijan); Ankara University, Department of Physics, Ankara (Turkey)
Neutrinoless $??$ decay nuclear matrix elements in an isotopic chain
We analyze nuclear matrix elements (NME) of neutrinoless double beta decay calculated for the Cadmium isotopes. Energy density functional methods including beyond mean field effects such as symmetry restoration and shape mixing are used. Strong shell effects are found associated to the underlying nuclear structure of the initial and final nuclei. Furthermore, we show that NME for two-neutrino double beta decay evaluated in the closure approximation, $M^{2\
Tom�s R. Rodr�guez; Gabriel Mart�nez-Pinedo
Constraining gamma from K* pi and rho K Decays
We show that information on the weak phase gamma can be extracted from the K* pi and rho K decays. Less hadronic uncertainty is involved when the observables of four of these modes are combined together. We further point out two approximate relations in these decay modes can help determine whether there are new physics contributions in Delta I = 1 transitions, as hinted in the K pi modes.
Bounds on Heavy-to-Heavy Weak Decay Form Factors
We provide upper and lower bounds on the semileptonic weak decay form factors for $B \\to D^(*)$ and $\\Lambda_b \\to \\Lambda_c$ decays by utilizing inclusive heavy quark effective theory sum rules. These bounds are calculated to second order in $\\Lambda_{QCD}/m_Q$ and first order in $\\alpha_s$. The $O(\\alpha_s^2 \\beta_0)$ corrections to the bounds at zero recoil are also presented.
Chiang, C W
We show that information on the weak phase gamma can be extracted from the K* pi and rho K decays. Less hadronic uncertainty is involved when the observables of four of these modes are combined together. We further point out two approximate relations in these decay modes can help us determining whether there are new physics contributions in Delta I = 1 transitions, as hinted in the K pi modes.
The strong coupling from tau decays without prejudice
We review our recent determination of the strong coupling \\alpha_s from the OPAL data for non-strange hadronic tau decays. We find that \\alpha_s(m^2_\\tau) =0.325+-0.018 using fixed-order perturbation theory, and \\alpha_s(m^2_\\tau)=0.347+-0.025 using contour-improved perturbation theory. At present, these values supersede any earlier determinations of the strong coupling from hadronic tau decays, including those from ALEPH data.
Boito, Diogo; Jamin, Matthias; Mahdavi, Andisheh; Maltman, Kim; Osborne, James; Peris, Santiago
Observation of Tau Decays with Two Neutral Kaons
We report on the observation of the decay \\Gamma ! K 0 K 0 \\Gamma in 3.11 fb \\Gamma1 of data taken with the CLEO II detector at the Cornell Electron Storage Ring. Both K 0 mesons are detected through their decays via K S ! + \\Gamma . Preliminary results on the branching fraction and on the resonant substructure are presented. In particular, we find B( \\Gamma ! K 0 K 0 \\Gamma ) = 0:083 \\Sigma 0:017 \\Sigma 0:017 %. We also comment on the sensitivity of the KK invariant mass spectrum to a non-zero tau-neutrino mass. Permanent address: University of Hawaii at Manoa y Permanent address: INP, Novosibirsk, Russia 2 I. INTRODUCTION Tau lepton decays of the type \\Gamma ! [KK] \\Gamma have been known to exist [1] for nearly a decade. However, due to the small decay width and difficulties associated with identifying kaons, little information is presently available for these decays. In this paper, we report on the observation of KK decays where both...
Balest Cho Ford; Ichep Ref; Gsl Cleo Conf; K. Cho; K. Lingel; M. Lohner; P. Rankin
Effects of Vacuum Fluctuation Suppression on Atomic Decay Rates
The use of atomic decay rates as a probe of sub-vacuum phenomena will be studied. Because electromagnetic vacuum fluctuations are essential for radiative decay of excited atomic states, decay rates can serve as a measure of the suppression of vacuum fluctuation in non-classical states, such as squeezed vacuum states. In such states the renormalized expectation value of the square of the electric field or the energy density can be periodically negative, representing suppression of vacuum fluctuations. We explore the extent to which atomic decays can be used to measure the mean squared electric field or energy density. We consider a scheme in which atoms in an excited state transit a closed cavity whose lowest mode contains photons in a non-classical state. The change in the decay probability of the atom in the cavity due to the non-classical state can, under certain circumstances, serve as a measure of the mean squared electric field or energy density in the cavity. We derive a quantum inequality bound on the decrease in this probability. We also show that the decrease in decay rate can sometimes be a measure of negative energy density or negative squared electric field. We make some estimates of the magnitude of this effect, which indicate that an experimental test might be possible.
L. H. Ford; Thomas A. Roman
Gamma-Ray Lines from Radiative Dark Matter Decay
The decay of dark matter particles which are coupled predominantly to charged leptons has been proposed as a possible origin of excess high-energy positrons and electrons observed by cosmic-ray telescopes PAMELA and Fermi LAT. Even though the dark matter itself is electrically neutral, the tree-level decay of dark matter into charged lepton pairs will generically induce radiative two-body decays of dark matter at the quantum level. Using an effective theory of leptophilic dark matter decay, we calculate the rates of radiative two-body decays for scalar and fermionic dark matter particles. Due to the absence of astrophysical sources of monochromatic gamma rays, the observation of a line in the diffuse gamma-ray spectrum would constitute a strong indication of a particle physics origin of these photons. We estimate the intensity of the gamma-ray line that may be present in the energy range of a few TeV if the dark matter decay interpretation of the leptonic cosmic-ray anomalies is correct and comment on observational prospects of present and future Imaging Cherenkov Telescopes, in particular the CTA.
Mathias Garny; Alejandro Ibarra; David Tran; Christoph Weniger
Higgs Boson Decays in the Minimal Supersymmetric Standard Model with Radiative Higgs Sector CP Violation
We re�evaluate the decays of the Higgs bosons in the minimal supersymmetric standard model (MSSM) where the tree-level CP invariance of the Higgs potential is explicitly broken by the loop effects of the third�generation squarks with CP�violating soft�breaking Yukawa interactions. This study is based on the mass matrix of the neutral Higgs bosons that is valid for arbitrary values of all the relevant MSSM parameters. It extends the previous work considerably by including neutral Higgs�boson decays into virtual gauge bosons and those into top�squark pairs, by implementing squark�loop contributions to the two�gluon decay channel, and by incorporating the decays of the charged Higgs boson. The constraints from the electron electric dipole moment on the CP phases are also discussed. We find that the branching fractions of both the neutral and charged Higgs�boson decays and their total decay widths depend strongly on the CP phases of the top (and bottom) squark sectors through the loop�induced neutral Higgs boson mixing as well as the direct couplings of the neutral Higgs bosons to top squark pairs. PACS number(s): 14.80.Cp, 11.30.Er, 12.60.Jv Typeset using REVTEX 1 I.
S. Y. Choi; Kaoru Hagiwara; Jae Sik Lee
Systematic gauge-invariant approach to heavy quarkonium decays
We present a method which, starting directly from QCD, permits a systematic gauge-invariant expansion to be made for all hard processes involving quarkonia in powers of the quark relative velocity, a small natural parameter for heavy quark systems. Our treatment automatically introduces soft gluons in the expansion. Corrections arising from the incorporation of gauge symmetry turn out to be important for decay and fragmentation processes involving {ital Q{bar Q}} systems. The contribution of soft gluons is shown to be of higher order in {ital v} and so is neglected for calculations done up to and including {ital O}({ital v}{sup 2}). {copyright} {ital 1996 The American Physical Society.}
Khan, H. [Department of Physics, Quaid-e-Azam University, Islamabad (Pakistan)] [Department of Physics, Quaid-e-Azam University, Islamabad (Pakistan); Hoodbhoy, P. [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)] [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); [Department of Physics, Quaid-e-Azam University, Islamabad (Pakistan)
Determination of alpha_s from tau decays
Hadronic tau decays offer the possibility of determining the strong coupling alpha_s at relatively low energy. Precisely for this reason, however, good control over the perturbative QCD corrections, the non-perturbative condensate contributions in the framework of the operator product expansion (OPE), as well as the corrections going beyond the OPE, the duality violations (DVs), is required. On the perturbative QCD side, the contour-improved versus fixed-order resummation of the series is still an issue, and will be discussed. Regarding the analysis, self-consistent fits to the data including all theory parameters have to be performed, and this is also explained in some detail. The fit quantities are moment integrals of the tau spectral function data in a certain energy window and care should be taken to have acceptable perturbative behaviour of those moments as well as control over higher-dimensional operator corrections in the OPE.
Jamin, Matthias
Measurements of B -> V gamma Decays
The standard model has been highly successful at describing current experimental data. However, extensions of the standard model predict particles that have masses at energy scales that are above the electroweak scale. The flavor-changing neutral current processes of the B meson are sensitive to the influences of these new physics contributions. These processes proceed through loop diagrams, thus allowing new physics to enter at the same order as the standard model. New physics may contribute to the enhancement or suppression of rate asymmetries or the decay rates of these processes. The transition B {yields} V{gamma} (V = K*(892), {rho}(770), {omega}(782), {phi}(1020)) represents radiative decays of the B meson that proceed through penguin processes. Hadronic uncertainties limit the theoretical accuracy of the prediction of the branching fractions. However, uncertainties, both theoretical and experimental, are much reduced when considering quantities involving ratios of branching fractions, such as CP or isospin asymmetries. The most dominant exclusive radiative b {yields} s transition is B {yields} K*{gamma}. We present the best measurements of the branching fractions, direct CP, and isospin asymmetries of B {yields} K*{gamma}. The analogous b {yields} d transitions are B {yields} {rho}{gamma} and B {yields} {omega}{gamma}, which are suppressed by a factor of |V{sub td}/V{sub ts}|{sup 2} {approx} 0.04 relative to B {yields} K*{gamma}. A measurement of the branching fractions and isospin asymmetry of B{sup +} {yields} {rho}{sup +}{gamma} and B{sup 0} {yields} {rho}{sup 0}{gamma}, as well as a search for B {yields} {omega}{gamma}, are also given. These measurements are combined to calculate the ratio of CKM matrix elements |V{sub td}/V{sub ts}|, which corresponds to the length of one side of the unitary triangle. Finally, we present a search for the penguin annihilation process B {yields}{phi}{gamma}. We use a sample of 383 million B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy B factory for the analysis of B {yields} K*{gamma}. We measure the branching fractions {Beta}(B{sup 0} {yields} K*{sup 0}{gamma}) = (4.47 {+-} 0.10 {+-} 0.16) x 10{sup -5} and {Beta}(B{sup +} {yields} K*{sup +}{gamma}) = (4.22 {+-} 0.14 {+-} 0.16) x 10{sup -5}. We measure the direct CP asymmetry to be -0.033 < {Alpha}{sub CP} (B {yields} K*{gamma}) < 0.028 and the isospin asymmetry to be 0.017 < {Delta}{sub 0-} < 0.116, where the limits are determined at the 90% C.L. and include both the statistical and systematic uncertainties. Using a sample of 347 million B{bar B} events, we measure the branching fractions {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) = (1.10{sub -0.33}{sup +0.37} {+-} 0.09) x 10{sup -6} and {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) = (0.79{sub -0.20}{sup +0.22} {+-} 0.06) x 10{sup -6}, the isospin asymmetry {Delta} = -0.35 {+-} 0.27, and set a 90% C.L. upper limit {Beta}(B {yields} {omega}{gamma}) < 0.78 x 10{sup -6}. We also measure the isospin-averaged branching fraction {Beta}(B {yields} ({rho}/{omega}){gamma}) = (1.25{sub -0.24}{sup +0.25} {+-} 0.09) x 10{sup -6}, from which we determine |V{sub td}/V{sub ts}|= 0.200{sub -0.020}{sup +0.021} {+-} 0.015, where the first uncertainty is experimental and the second theoretical. Finally, a sample of 124 million B{bar B} events is used to set an upper limit of {Beta}(B {yields} {phi}{gamma}) < 8.5 x 10{sup -7} at the 90% C.L.
Yarritu, Aaron K.; /Stanford U., Phys. Dept.
Flavour oscillations and CP asymmetry in semileptonic Bs0 decays
The B{sub s}{sup 0} meson spontaneously transforms into its antiparticle ({bar B}{sub s}{sup 0}). These 'flavour oscillations' occur periodically with a frequency that may be measured. The oscillation frequency is related to the fundamental parameters of the electroweak interaction. Measuring the frequency provides a constraint on the electroweak quark coupling parameter V{sub ts} and improves the constraint on V{sub td}. Furthermore, the amplitude of the oscillation process may be slightly different in B{sub s}{sup 0} and {bar B}{sub s}{sup 0} mesons due to CP violating nature of the weak interaction. This 'asymmetry' is expected to be small (a{sub fs}{sup SM,s} = (2.06 {+-} 0.57) {center_dot} 10{sup -5}), but may be enhanced (a{sub fs}{sup s} {approx_equal} {Omicron}(1%)) by new sources of CP violation. This thesis describes a search for B{sub s}{sup 0} flavour oscillations and charge asymmetry in the B{sub s}{sup 0} {yields} D{sub s}{sup -}{mu}{sup +}{nu}{sub {mu}}X (D{sub s}{sup -} {yields} K*{sup 0}K{sup -}) decay mode using 5.0 fb{sup -1} of D0 data. A lower limit is placed on the oscillation frequency, {Delta}m{sub s} > 9.9 ps{sup -1} with an expected sensitivity to oscillations below 14.8 ps{sup -1}. The charge asymmetry is measured to be a{sub fs}{sup s} = 0.018 {+-} 0.025(stat) {+-} 0.002(syst). A combination of these measurements with other decay modes is also presented.
Beale, Steven Thomas; /York U., Canada
Interatomic Coulombic decay following Ne 1s Auger decay in NeAr
Using momentum-resolved electron-ion multicoincidence spectroscopy, we have investigated interatomic Coulombic decay (ICD) in the heteronuclear NeAr dimer following Ne 1s Auger decay. The measured intensity ratio for the three ICD transitions Ne{sup 2+}(2s{sup -1}2p{sup -1} {sup 1}P)Ar to Ne{sup 2+}(2p{sup -2} {sup 1}S)-Ar{sup +}(3p{sup -1}), Ne{sup 2+}(2s{sup -1}2p{sup -1} {sup 1}P)Ar to Ne{sup 2+}(2p{sup -2} {sup 1}D)-Ar{sup +}(3p{sup -1}), and Ne{sup 2+}(2s{sup -1}2p{sup -1} {sup 3}P)Ar to Ne{sup 2+}(2p{sup -2} {sup 3}P)-Ar{sup +}(3p{sup -1}) reasonably agree with predictions. The kinetic energy release distribution for the fragmentation to Ne{sup 2+}(2p{sup -2} {sup 1}D)-Ar{sup +}(3p{sup -1}) after the ICD transition from singlet Ne{sup 2+}(2s{sup -1}2p{sup -1} {sup 1}P)Ar state, which is a mirror image of the kinetic energy distribution of the emitted ICD electrons, suggests that the corresponding ICD rate is roughly two times lower than predicted by ab initio calculations.
Ouchi, T.; Sakai, K.; Fukuzawa, H.; Ueda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Higuchi, I.; Tamenori, Y. [Japan Synchrotron Radiation Research Institute, Sayo, Hyogo 679-5198 (Japan); Demekhin, Ph. V.; Chiang, Y.-C.; Stoychev, S. D.; Kuleff, A. I. [Theoretische Chemie, Universitaet Heidelberg, D-69120 Heidelberg (Germany); Mazza, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Cimaina and Dipartimento di Fisica, Universita degli Studi di Milano, via Celoria 16, I-20133 Milano (Italy); Schoeffler, M. [Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Nagaya, K.; Yao, M. [Department of Physics, Kyoto University, Kyoto 606-8502 (Japan); Saito, N. [National Institute of Advanced Industrial Science and Technology, National Meteorology Institute of Japan, Tsukuba 305-8568 (Japan)
Kinetics of fluorescein decay and its application as a geothermal tracer
This paper reports on fluorescent which is a dye used to trace the path of injected fluids through geothermal reservoirs. The authors have measured its thermal stability at temperatures up to 300{degrees} C in hydrothermal autoclaves at various fluid compositions, pHs, and oxygen concentrations. The results of these experiments indicate that fluorescein will decay less than 10% during a one month tracer test in geothermal reservoirs with temperatures below 210{degrees} C. For tracer test involving longer times and/or higher temperatures, the activation parameters presented in this study can be used to correct for thermal decay. These parameters were applied to a tracer test conducted at the Dixie Valley, Nevada geothermal system to correct for the thermal decay of fluorescein and to deduce the effective temperature of the injection-production flow path.
Adams, M.C.; Davis, J. (Univ. of Utah Research Inst., Salt Lake City, UT (US))
The use of atomic decay rates as a probe of sub-vacuum phenomena will be studied. Because electromagnetic vacuum fluctuations are essential for radiative decay of excited atomic states, decay rates can serve as a measure of the suppression of vacuum fluctuation in non-classical states, such as squeezed vacuum states. In such states the renormalized expectation value of the square of the electric field or the energy density can be periodically negative, representing suppression of vacuum fluctuations. We explore the extent to which atomic decays can be used to measure the mean squared electric field or energy density. We consider a scheme in which atoms in an excited state transit a closed cavity whose lowest mode contains photons in a non-classical state. The change in the decay probability of the atom in the cavity due to the non-classical state can, under certain circumstances, serve as a measure of the mean squared electric field or energy density in the cavity. We derive a quantum inequality bound on the ...
Ford, L H
Beta decay of Neutron-Rich 53-56Ca
Beta-decay properties of neutron-rich Ca isotopes have been obtained. Half-life values were determined for the first time for 54Ca [86(7) ms], 55Ca [22(2) ms], and 56Ca [11(2) ms]. The half-life of 230(6) ms deduced for 53Ca is significantly longer than reported previously, where the decay chain 53K -> 53Ca -> 53Sc was considered. A delayed gamma ray with energy 247 keV as identified following beta decay of 54Ca, and is proposed to depopulate the first 1+ level in 54Sc. The beta-decay properties compare favorably with the results of shell model calculations completed in the full pf-space with the GXPF1 interaction. The half-lives of the neutron-rich Ca isotopes are also compared with gross beta-decay theory. The systematic trend of the neutron-rich Ca half-lives is consistent with the presence of a subshell gap at N=32.
P. F. Mantica; R. Broda; H. L. Crawford; A. Damaske; B. Fornal; A. A. Hecht; C. Hoffman; M. Horoi; N. Hoteling; R. V. F. Janssens; J. Pereira; J. S. Pinter; J. B. Stoker; S. L. Tabor; T. Sumikama; W. B. Walters; X. Wang; S. Zhu
Mantica, P F; Crawford, H L; Damaske, A; Fornal, B; Hecht, A A; Hoffman, C; Horoi, M; Hoteling, N; Janssens, R V F; Pereira, J; Pinter, J S; Stoker, J B; Tabor, S L; Sumikama, T; Walters, W B; Wang, X; Zhu, S
Decay studies of the highly neutron-deficient indium isotopes
An extension of the experimentally known nuclidic mass surface to nuclei far from the region of beta-stability is of fundamental interest in providing a better determination of the input parameters for the various nuclear mass formulae, allowing a more accurate prediction of the ultimate limits of nuclear stability. In addition, a study of the shape of the mass surface in the vicinity of the doubly-closed nuclide /sup 100/Sn provides initial information on the behavior of the shell closure to be expected when Z = N = 50. Experiments measuring the decay energies of /sup 103/ /sup 105/In by ..beta..-endpoint measurements are described with special attention focused on the development of a plastic scintillator ..beta..-telescope coupled to the on-line mass separator RAMA (Recoil Atom Mass Analyzer). An attempt to measure the ..beta..-endpoint energy of /sup 102/In is also briefly described. The experimentally determined decay energies and derived masses for /sup 103/ /sup 105/In are compared with the predictions of different mass models to identify which models are more successful in this region. Furthermore, the inclusion in these comparisons of the available data on the neutron-rich indium nuclei permits a systematic study of their ground state mass behavior as a function of the neutron number between the shell closures at N = 50 and N = 82. These analyses indicate that the binding energy of /sup 103/In is 1 MeV larger than predicted by the majority of the mass models. An examination of the Q/sub EC/ surface and the single- and two-neutron separation energies in the vicinity of /sup 103/ /sup 105/In is also performed to investigate further the deviation and other possible systematic variations in the mass surface in a model-independent way.
Wouters, J.M.
Charmonium Decays to Axial-Vector Plus Pseudoscalar Mesons
A sample of 3.79{times}10{sup 6} {psi}(2S) events is used to study the decays of charmonium to axial-vector plus pseudoscalar mesons. The branching fraction for the decay {psi}(2S){r_arrow}b{sup {plus_minus}}{sub 1} (1235){pi}{sup {minus_plus}} agrees with expectations based on scaling the corresponding J/{psi} branching fraction. Flavor-SU(3)-violating K{sub 1}(1270) -K{sub 1}(1400) asymmetries with opposite character for {psi}(2S) and J/{psi} decays are observed. This contrasting behavior cannot be accommodated by adjustments of the singlet-triplet mixing angle. {copyright} {ital 1999} {ital The American Physical Society}
Bai, J.Z.; Bian, J.G.; Chen, G.P.; Chen, J.C.; Chen, Y.; Chen, Y.B.; Chen, Y.Q.; Cheng, B.S.; Cui, X.Z.; Ding, H.L.; Dong, L.Y.; Du, Z.Z.; Gao, C.S.; Gao, M.L.; Gao, S.Q.; Gu, J.H.; Gu, S.D.; Gu, W.X.; Gu, Y.F.; Guo, Y.N.; Han, S.W.; Han, Y.; He, J.; He, J.T.; He, K.L.; Hu, G.Y.; Hu, H.M.; Hu, J.L.; Hu, Q.H.; Hu, T.; Hu, X.Q.; Huang, Y.Z.; Jiang, C.H.; Jin, Y.; Ke, Z.J.; Lai, Y.F.; Lang, P.F.; Li, C.G.; Li, D.; Li, H.B.; Li, J.; Li, P.Q.; Li, R.B.; Li, W.; Li, W.G.; Li, X.H.; Li, X.N.; Liu, H.M.; Liu, J.; Liu, R.G.; Liu, Y.; Lu, F.; Lu, J.G.; Luo, X.L.; Ma, E.C.; Ma, J.M.; Mao, H.S.; Mao, Z.P.; Meng, X.C.; Nie, J.; Qi, N.D.; Qi, X.R.; Qiu, J.F.; Qu, Y.H.; Que, Y.K.; Rong, G.; Shao, Y.Y.; Shen, B.W.; Shen, D.L.; Shen, H.; Shen, X.Y.; Sheng, H.Y.; Shi, H.Z.; Song, X.F.; Sun, F.; Sun, H.S.; Sun, Y.; Sun, Y.Z.; Tang, S.Q.; Tong, G.L.; Wang, F.; Wang, L.S.; Wang, L.Z.; Wang, M.; Wang, P.; Wang, P.L.; Wang, S.M.; Wang, T.J.; Wang, Y.Y.; Wei, C.L.; Wu, Y.G.; Xi, D.M.; Xia, X.M.; Xie, P.P.; Xie, Y.; Xie, Y.H.; Xu, G.F.; Xue, S.T.; Yan, J.; Yan, W.G.; Yang, C.M.; Yang, C.Y.; Yang, J.; Yang, X.F.; Ye, M.H.; Yu, C.S.; Yu, C.X.; Yu, G.W.; Yu, Z.Q.; Yuan, C.Z.; Yuan, Y.; Zhang, B.Y.; Zhang, C.C.; Zhang, D.H.; Zhang, D.; Zhang, H.L.; Zhang, J.; Zhang, J.W.; Zhang, L.S.; Zhang, Q.J.; Zhang, S.Q.; Zhang, Y.Y.; Zhao, D.X.; Zhao, H.W.; Zhao, J.W.; Zhao, M.; Zhao, W.R.; Zhao, Z.G.; Zheng, J.P.; Zheng, L.S.; Zheng, Z.P.; Zhou, B.Q.; Zhou, G.P.; Zhou, H.S.; Zhou, L.; Zhu, K.J.; Zhu, Q.M.; Zhu, Y.C.; Zhu, Y.S.; Zhuang, B.A. [Institute of High Energy Physics, Beijing 100039, People`s Republic of (China)] [Institute of High Energy Physics, Beijing 100039, People`s Republic of (China); Hitlin, D.G.; Kelsey, M.H.; Oyang, J.; Panetta, J.; Porter, F.; Weaver, M. [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States); Chen, J.; Malchow, R.; Toki, W.; Yang, W. [Colorado State University, Fort Collins, Colorado 80523 (United States)] [Colorado State University, Fort Collins, Colorado 80523 (United States); Yu, Y.H. [Hangzhou Unv., Hangzhou 310028, People`s Republic of (China)] [Hangzhou Unv., Hangzhou 310028, People`s Republic of (China); Ban, Y. [Peking Unv. (China)] [Peking Unv. (China)
Updated measurements of hadronic B decays at CDF
The CDF experiment at the Tevatron p{bar p} collider established that extensive and detailed exploration of the b-quark dynamics is possible in hadron collisions, with results competitive and supplementary to those from e{sup +}e{sup -} colliders. This provides a rich, and highly rewarding program that has currently reached full maturity. In the following I report some recent results on hadronic decays: the evidence for the charmless annihilation decay mode B{sub s}{sup 0} {yields} {pi}{sup +}{pi}{sup -}, and the first reconstruction in hadron collisions of the suppressed decays B{sup -} {yields} D({yields} K{sup +}{pi}{sup 0})K{sup -} and B{sup -} {yields} D({yields} K{sup +} {pi}{sup -}){pi}{sup -}.
Morello, Michael J.
Decays of electron Bernstein waves near plasma edge
Nonlinear wave-wave couplings near the upper hybrid resonance are studied via particle-in-cell simulations. It is found that the decay of an electron Bernstein wave (EBW) depends on the ratio of the incident frequency and electron cyclotron frequency. For ratios less than two, parametric decay into a lower hybrid wave (or an ion Bernstein wave) and EBWs at a lower frequency is observed. For ratios larger than two, the daughter waves could be an electron cyclotron quasi-mode and another EBW or an ion wave and EBW. For sufficiently high incident power, the former process may dominate. Because of the electron cyclotron quasi-mode, electrons can be strongly heated by nonlinear Landau damping. As a result, the bulk of the incident power can be absorbed near plasma edge at high power. The increase in number of decay channels with frequency implies that the allowable power into the plasma must decrease with frequency.
Xiang Nong [Institute of Plasma Physics, CAS, Hefei, Anhui 230031 (China); Center for Integrated Plasma Studies, University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Cary, John R. [Center for Integrated Plasma Studies, University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Tech-X Corporation, Boulder, Colorado 80303 (United States)
Evidence for the decay X(3872) -> J/\\psi\\omega
We present a study of the decays B{sup 0,+} --> J/{psi}{pi}{sup +}{pi}{sup -}{pi}{sup 0}K{sup 0,+}, using 467x10{sup 6} B{anti B} pairs recorded with the BABAR detector. We present evidence for the decay mode X(3872) --> J/{psi}{omega}, with product branching fractions B(B{sup +} --> X(3872)K{sup +}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.2(stat) {+-} 0.1(syst)] x 10{sup -5}, and B(B{sup 0} --> X(3872)K{sup 0}) x B(X(3872) --> J/{psi}{omega}) = [0.6 {+-} 0.3(stat) {+-} 0.1(syst)] x 10{sup -5}. A detailed study of the {pi}{sup +}{pi}{sup -}{pi}{sup 0} mass distribution from X(3872) decay favors a negative-parity assignment.
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
Precision Measurements of Tau Lepton Decays
Using data collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV, the branching fractions {Beta}({tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (8.83 {+-} 0.01 {+-} 0.13)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}) = (0.273 {+-} 0.002 {+-} 0.009)%, {Beta}({tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}}) = (0.1346 {+-} 0.0010 {+-} 0.0036)%, and {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}) = (1.58 {+-} 0.13 {+-} 0.12) x 10{sup -5} are measured where the uncertainties are statistical and systematic, respectively. The invariant mass distribution for the {tau}{sup -} {yields} {pi}{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}} {yields} K{sup -}{pi}{sup -}{pi}{sup +}{nu}{sub {tau}}, {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} decays are unfolded to correct for detector effects. A measurement of {Beta}({tau}{sup -} {yields} {phi}{pi}{sup -}{nu}{sub {tau}}) = (3.42 {+-} 0.55 {+-} 0.25) x 10{sup -5}, a measurement of {Beta}({tau}{sup -} {yields} {phi}K{sup -}{nu}{sub {tau}}) = (3.39 {+-} 0.20 {+-} 0.28) x 10{sup -5} and an upper limit on {Beta}({tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}}[ex.{phi}]) {le} 2.5 x 10{sup -6} {at} 905 CL are determined from a binned maximum likelihood fit of the {tau}{sup -} {yields} K{sup -}{pi}{sup -}K{sup +}{nu}{sub {tau}} and {tau}{sup -} {yields} K{sup -}K{sup -}K{sup +}{nu}{sub {tau}} K{sup +}K{sup -} invariant mass distributions. The branching ratio {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}}) is measured to be (6.531 {+-} 0.056 {+-} 0.093) x 10{sup -2} from which |V{sub us}| is determined to be 0.2255 {+-} 0.0023. The branching ratio {Beta}/({tau}{sup -} {yields} {mu}{nu}{sub {tau}}{bar {nu}}{sub {mu}})/{Beta}({tau}{sup -} {yields} e{sup -} {nu}{sub {tau}}{bar {nu}}{sub e}) = (9.796 {+-} 0.016 {+-} 0.035) x 10{sup -1} is measured enabling a precision test of the Standard Model assumption of charged current lepton universality, g{sub {mu}}/g{sub e} = 1.0036 {+-} 0.0020. The branching ratios {Beta}({tau}{sup -} {yields} K{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{sup -}{nu}{sub {tau}}{bar {nu}}{sub e}) = (3.882 {+-} 0.032 {+-} 0.057) x 10{sup -2}, and {Beta}({tau}{sup -} {yields} {pi}{sup -}{nu}{sub {tau}})/{Beta}({tau}{sup -} {yields} e{nu}{sub {tau}}{bar {nu}}{sub e}) = (5.9545 {+-} 0.014 {+-} 0.061) x 10{sup -1} are measured which provide additional tests of charged current lepton universality, (g{sub {tau}}/g{sub {mu}}){sub {pi}} = 0.9856 {+-} 0.0057 and (g{sub {tau}}/g{sub {mu}}){sub K} = 0.9827 {+-} 0.0086 which can be combined to give (g{sub {tau}}/g{sub {mu}}){sub {pi}/K} = 0.9850 {+-} 0.0054. Any deviation of these measurements from the expected Standard Model values would be an indication of new physics.
Nugent, Ian M.; /Victoria U.
New Limit on Time-Reversal Violation in Beta Decay
We report the results of an improved determination of the triple correlation DP{center_dot}(p{sub e}xp{sub v}) that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to the standard model. Our result is D=[-0.96{+-}1.89(stat){+-}1.01(sys)]x10{sup -4}. The corresponding phase between g{sub A} and g{sub V} is {phi}{sub AV}=180.013 deg. {+-}0.028 deg. (68% confidence level). This result represents the most sensitive measurement of D in nuclear {beta} decay.
Mumm, H. P. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); CENPA and Physics Department, University of Washington, Seattle, Washington 98195 (United States); Chupp, T. E.; Cooper, R. L.; Coulter, K. P. [Physics Department, University of Michigan, Ann Arbor, Michigan, 48104 (United States); Freedman, S. J.; Fujikawa, B. K. [Physics Department, University of California at Berkeley and Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Garcia, A. [CENPA and Physics Department, University of Washington, Seattle, Washington 98195 (United States); Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Jones, G. L. [Physics Department, Hamilton College, Clinton, New York 13323 (United States); Nico, J. S.; Thompson, A. K. [National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States); Trull, C. A.; Wietfeldt, F. E. [Physics Department, Tulane University, New Orleans, Louisiana 70118 (United States); Wilkerson, J. F. [Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599 (United States); CENPA and Physics Department, University of Washington, Seattle, Washington 98195 (United States)
Brief report on `Radiative $\\phi$ decays with derivative interactions'
We study the line shapes of radiative $\\phi$-decays with a direct coupling of the $\\phi$ meson to the $f_{0}(980)$ and $a_{0}(980)$ scalar mesons. The latter couple via derivative interactions to $\\pi_0 \\pi_0$ and $\\pi_0 \\eta$, respectively. Although the kaon-loop mechanism is usually regarded as the dominant mechanism in radiative $\\phi$ decays, here we test a different possibility: we set the kaon-loop to zero and we fit the theoretical curves to the data by retaining only the direct coupling. Remarkably, satisfactory fits can be achieved, mainly due to the effects of derivative interactions of scalar with pseudoscalar mesons.
Giacosa, F
Determining the Energy Barrier for Decay out of Superdeformed Bands
An asymptotically exact quantum mechanical calculation of the matrix elements for tunneling through an asymmetric barrier is combined with the two-state statistical model for decay out of superdeformed bands to determine the energy barrier (as a function of spin) separating the superdeformed and normal-deformed wells for several nuclei in the 190 and 150 mass regions. The spin-dependence of the barrier leading to sudden decay out is shown to be consistent with the decrease of a centrifugal barrier with decreasing angular momentum. Values of the barrier frequency in the two mass regions are predicted.
B. R. Barrett; J. B�rki; D. M. Cardamone; C. A. Stafford; D. L. Stein
Can the beta decay of neutral kaons be observed?
The rate of the beta decay of neutral kaons is calculated within the meson dominance approach taking into account the relation between the KK\\rho and \\pi\\pi\\rho coupling constants which follows from the vector meson dominance in electromagnetic interactions and isospin symmetry. The decay rate transforms into the following branching fraction summed over the charge states indicated: B(K0L -> K+- e-+ nu)=(2.53+-0.10)x10^{-9}. The error is dominated by our estimate of isospin violating effects. Experimental aspects of such a measurement are discussed.
Peter Lichard; Julia Thompson
Computer simulations of the motion and decay of global strings
Computer simulations have been carried out of the motion and decay of global strings, including spectrum analysis of the energy stored in the scalar field which describes the global string and the radiated Nambu-Goldstone bosons. We simulated relaxing pieces of bent string and collapsing loops. We find, for the string sizes investigated, that the spectrum of field energy hardens rather than softens while the string decays into Nambu-Goldstone radiation. We argue on theoretical grounds that is indeed the most plausible general behaviour. 19 refs., 12 figs.
Hagmann, C.; Sikivie, P.
A Search for Neutrinoless Tau Decays to Three Leptons
Using approximately 350 million {tau}{sup +}{tau}{sup -} pair events recorded with the BaBar detector at the Stanford Linear Accelerator Center between 1999 and 2006, a search has been made for neutrinoless, lepton-flavor violating tau decays to three lighter leptons. All six decay modes consistent with conservation of electric charge and energy have been considered. With signal selection efficiencies of 5-12%, we obtain 90% confidence level upper limits on the branching fraction {Beta}({tau} {yields} {ell}{ell}{ell}) in the range (4-8) x 10{sup -8}.
Kolb, Jeffrey A.; /Oregon U. /SLAC
Time-resolved fluorescence decay measurements for flowing particles
DOE Patents (OSTI)
Time-resolved fluorescence decay measurements are disclosed for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated CW laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes. 12 figs.
Deka, C.; Steinkamp, J.A.
Decay modes of $^{10}$C nuclei unbound state
Unbound states of $^{10}$C nuclei produced as quasi-projectiles in $^{12}$C+$^{24}$Mg collisions at E/A = 53 and 95 MeV are studied with the Indra detector array. Multi-particle correlation function analyses provide experimental evidence of sequential de-excitation mechanisms through the production of intermediate $^{9}$B, $^{6}$Be and $^{8}$Be unbound nuclei. The relative contributions of different decay sequences to the total decay width of the explored states is estimated semi-quantitatively. The obtained results show that heavy-ion collisions can be used as a tool to access spectroscopic information about exotic nuclei.
F. Grenier; A. Chbihi; R. Roy; G. Verde; D. Th�riault; J. D. Frankland; J. P. Wieleczko; B. Borderie; R. Bougault; R. Dayras; E. Galichet; D. Guinet; P. Lautesse; N. Le Neindre; O. Lopez; J. Moisan; L. Nalpas; M. P�rlog; M. F. Rivet; E. Rosato; B. Tamain; E. Vient; M. Vigilante
Closed-Form E1 Radiative Strength Functions for Gamma-Decay and Photoabsorption
Photoabsorption cross sections and {gamma}-decay strength functions are calculated and compared with experimental data to test simple phenomenological models of E1 gamma-strength description in the middle-weight and heavy atomic nuclei. Radiative strength functions with energy asymmetric shape are recommended for overall estimation of averaged gamma-strengths. Systematics for giant dipole resonance (GDR) parameters are given.
Plujko, Vladimir A.; Kadenko, Igor M.; Kulich, Elizaveta V.; Gorbachenko, Oleksandr M. [Nuclear Physics Department, Taras Shevchenko National University, Pr. Acad. Glushkova, 2, bldg. 11, 03022 Kyiv (Ukraine)
2p-2p decay of {sup 8}C and isospin-allowed 2p decay of the isobaric-analog state in {sup 8}B
{sup 8}C is found to decay to four protons and an {alpha} particle in two 2p emission steps. The correlations between the protons in the first step ({sup 8}C to {sup 6}Be) exhibit a significant enhancement in the region of the decay phase space where the two protons have small relative energy, a region sometimes called the diproton region. The decay of the isobaric analog of {sup 8}C in {sup 8}B is also found to decay by 2p emission. This is the first case of isospin-allowed 2p decay between isobaric analog states.
Charity, R. J.; Elson, J. M. [Department of Chemistry, Washington University, St. Louis, Missouri 63130 (United States); Manfredi, J.; Shane, R. [Department of Physics, Washington University, St. Louis, Missouri 63130 (United States); Sobotka, L. G. [Department of Chemistry, Washington University, St. Louis, Missouri 63130 (United States); Department of Physics, Washington University, St. Louis, Missouri 63130 (United States); Chajecki, Z.; Coupland, D.; Iwasaki, H.; Kilburn, M.; Lee, Jenny; Lynch, W. G.; Sanetullaev, A.; Tsang, M. B.; Winkelbauer, J.; Youngs, M. [Department of Physics and Astronomy, National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Marley, S. T.; Shetty, D. V.; Wuosmaa, A. H. [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008 (United States); Ghosh, T. K. [Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064 (India); Howard, M. E. [Department of Physics and Astronomy, Rutgers University, New Brunswick, New Jersey 08903 (United States)
Spectral Content of 22Na/44Ti Decay Data: Implications for a Solar Influence
We report a reanalysis of data on the measured decay rate ratio $^{22}$Na/$^{44}$Ti which were originally published by Norman et al., and interpreted as supporting the conventional hypothesis that nuclear decay rates are constant and not affected by outside influences. We find upon a more detailed analysis of both the amplitude and the phase of the Norman data that they actually favor the presence of an annual variation in $^{22}$Na/$^{44}$Ti, albeit weakly. Moreover, this conclusion holds for a broad range of parameters describing the amplitude and phase of an annual sinusoidal variation in these data. The results from this and related analyses underscore the growing importance of phase considerations in understanding the possible influence of the Sun on nuclear decays. Our conclusions with respect to the phase of the Norman data are consistent with independent analyses of solar neutrino data obtained at Super-Kamiokande-I and the Sudbury Neutrino Observatory (SNO).
Daniel O'Keefe; Brittany L. Morreale; Robert H. Lee; John B. Buncher; Ephraim Fischbach; Tom Gruenwald; Jere H. Jenkins; Daniel Javorsek II; Peter A. Sturrock
Charged-Higgs-boson search via heavy-top-quark decay at Fermilab Tevatron collider energy
Assuming a top-quark mass of about 150 GeV we analyze the prospects for a charged-Higgs-boson search in top-quark decay at the Fermilab Tevatron upgrade. Universality predicts the relative size of the top decay signal via {ital W} boson in different decay channels, and an observable excess over this prediction can be used as a signature for charged-Higgs-boson production. In the charged-Higgs-boson--fermion coupling scheme suggested by minimal supersymmetry and E{sub 6} string-inspired models one expects to see an observable signal up to a charged-Higgs-boson mass of 100 GeV throughout the allowed range of the coupling parameter tan{beta}. The absence of such a signal would give an unambiguous charged-Higgs-boson mass limit of 100 GeV. This is not possible however in the alternative coupling schemes of two-Higgs-doublet models.
Godbole, R.M. (Department of Physics, University of Bombay, Bombay 400098 (India)); Roy, D.P. (Tata Institute of Fundamental Research, Homi Bhabha Road, Bombay 400005 (India))
Decay widths of ground-state and excited {Xi}{sub b} baryons in a nonrelativistic quark model
Decay processes of ground and excited bottom baryons are studied in the {sup 3}P{sub 0} nonrelativistic quark model with all model parameters fixed in the sector of light quarks. Using as an input the recent mass of {Xi}{sub b} and the theoretical masses of {Xi}{sub b}{sup *} and {Xi}{sub b}{sup '}, narrow decay widths are predicted for the ground-state bottom baryons {Xi}{sub b}{sup *} and {Xi}{sub b}{sup '}. The work predicts large decay widths, about 100 MeV for the {rho}-type orbital excitation states of {Xi}{sub b}.
Limphirat, Ayut [School of Physics, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand); Department of Applied Physics, Faculty of Sciences and Liberal Arts, Rajamangala University of Technology Isan, Nakhon Ratchasima 30000 (Thailand); Kobdaj, Chinorat; Suebka, Prasart; Yan, Yupeng [School of Physics, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Thailand Center of Excellence in Physics (ThEP), Commission on Higher Education, Bangkok 10400 (Thailand)
Exclusive hadronic B decays to charm and charmonium final states
We have fully reconstructed decays of both B0 and B- Mesons into final states containing either D, D*, D**, Psi, Psi', or Chi_{c1} mesons. This allows us to obtain new results on many physics topics including branching ratios, tests of the factorization hypothesis, color suppression, resonant substructure, and the B- - B0 mass difference.
Alam, M S; Nemati, B; O'Neill, J J; Severini, H; Sun, C R; Zoeller, M M; Crawford, G; Daubenmier, C M; Fulton, R; Fujino, D; Gan, K K; Honscheid, K; Kagan, H; Kass, R; Lee, J; Malchow, R L; Morrow, F H; Skovpen, Y; Sung, M; White, C; Butler, F; Fu, X; Kalbfleisch, G R; Ross, W R; Skubic, P L; Snow, J; Wang, P L; Wood, M; Brown, D N; Fast, J; McIlwain, R L; Miao, T; Miller, D H; Modesitt, M; Payne, D; Shibata, E I; Shipsey, I P J; Wang Pei Ning; Battle, M; Ernst, J; Kwon, Y; Roberts, S; Thorndike, E H; Wang, C H; Dominick, J; Lambrecht, M; Sanghera, S; Shelkov, V; Skwarnicki, T; Stroynowski, R; Volobuev, I P; Wei, G; Zadorozhny, P; Artuso, M; Goldberg, M; He, D; Horwitz, N; Kennett, R; Mountain, R; Moneti, G C; Muheim, F; Mukhin, Y; Playfer, S; Rozen, Y; Stone, S; Thulasidas, M; Vasseur, G; Zhu, G; Bartelt, J; Csorna, S E; Egyed, Z; Jain, V; Kinoshita, K; Edwards, K W; Ogg, M; Britton, D I; Hyatt, E R F; MacFarlane, D B; Patel, P M; Akerib, D S; Barish, B C; Chadha, M; Chan, S; Cowen, D F; Eigen, G; Miller, J S; O'Grady, C; Urheim, J; Weinstein, A J; Acosta, D; Athanas, M; Masek, G E; Paar, H P; Gronberg, J B; Kutschke, R; Menary, S R; Morrison, R J; Nakanishi, S; Nelson, H N; Nelson, T K; Qiao, C; Richman, J D; Ryd, A; Tajima, H; Schmidt, D; Sperka, D; Witherell, M S; Procario, M; Balest, R; Cho, K; Daoudi, M; Ford, W T; Johnson, D R; Lingel, K; Lohner, M; Rankin, P; Smith, J G; Alexander, J P; Bebek, C; Berkelman, K; Bloom, K; Browder, T E; Cassel, David G; Cho, H A; Coffman, D M; Drell, P S; Ehrlich, R; Garc�a-Sciveres, M; Geiser, B; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Jones, C D; Jones, S L; Kandaswamy, J; Katayama, N; Kim, P C; Kreinick, D L; Ludwig, G S; Masui, J; Mevissen, J; Mistry, N B; Ng, C R; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Salman, S; Sapper, M; W�rthwein, F; Avery, P; Freyberger, A P; Rodr�guez, J; Stephens, R; Yang, S; Yelton, J; Cinabro, D; Henderson, S; Liu, T; Saulnier, M; Wilson, R; Yamamoto, H; Bergfeld, T; Eisenstein, B I; Gollin, G; Ong, B; Palmer, M; Selen, M; Thaler, J J; Sadoff, A J; Ammar, R; Ball, S; Baringer, P; Bean, A; Besson, D; Coppage, D; Copty, N K; Davis, R; Hancock, N; Kelly, M; Kwak, N; Lam, H; Kubota, Y; Lattery, M; Nelson, J K; Patton, S; Perticone, D; Poling, R A; Savinov, V; Schrenk, S; Wang, R; CLEO collaboration
Nuclear Structure and Decay Data: Current Status and Future Perspectives
The nuclear structure databases provide physicists around the world with a useful collection of reliable and well documented datasets. The Evaluated Nuclear Structure Data File (ENSDF) database produced by the International Nuclear Structure and Decay Data Network (NSDD) under the auspices of the International Atomic Energy Agency (IAEA)
Filip G. Kondev; Jagdish K. Tuli; International Nuclear Structure and Decay Data Network
Decay to bound states of a soliton in a well
The decay of a soliton in a trapped state inside a well is shown numerically. Bound states of a kink in an attractive well, both centered and off center are found. Their stability is studied. Unstable soliton solutions inside a repulsive barrier are also found.
G. K�lbermann
Prompt Neutron Decay Constant from Feynman Variance Fitting
The use of fast-response liquid scintillators for passive measurements with highly enriched uranium (HEU) castings provides information on the timescale of the fission chain multiplication process for HEU. Thus, these detectors produce time responses characteristic of the HEU and not the moderator around 3He counters. Up to five HEU castings were assembled and the passive time coincidence measurements performed. The prompt neutron decay constants inferred from the Feynman variance data with the arrays of large liquid scintillators are compared with decay constants obtained from previously presented Feynman variance data collected in active interrogation measurements with these same HEU castings. The active measurements used plastic scintillation detectors adjacent to the castings to eliminate time-of-flight effects and showed that the prompt neutron decay constant is clearly not exponential. However, time-of-flight effects in the passive measurements result in exponential behavior and allow the Feynman variance data to be fit with the well-known point kinetics analytical formula. The characterization of the prompt neutron decay constant is investigated by comparing the results of the passive and active measurement data.
McConchie, Seth M [ORNL; Hausladen, Paul [ORNL; Mihalczo, John T [ORNL
Search for higgs boson diphoton decay with CMS at LHC
We have carried out a detailed study of the inclusive search for the Higgs boson in diphoton decay channel with CMS detector at LHC. The analysis is based on full Monte Carlo simulation. Though for the moment we have only simulated data to work with, ...
Harvey Newman
One-nucleon-induced nonmesonic hypernuclear decay in laboratory coordinates
We present a formalism for the computation of one-nucleon-induced nonmesonic weak hypernuclear decay rates in laboratory coordinates, within an independent-particle shell model framework, with a view to its generalization to the case of two-nucleon-induced transitions.
Galeao, A. P. [Instituto de Fisica Teorica, UNESP, 01140-070 Sao Paulo, SP (Brazil); Barbero, C. [Facultad de Ciencias Exactas, UNLP, 1900 La Plata (Argentina) and Instituto de Fisica La Plata, CONICET, 1900 La Plata (Argentina); De Conti, C. [Campus Experimental de Itapeva, UNESP, 18409-010 Itapeva, SP (Brazil); Krmpotic, F. [Facultad de Ciencias Astronomicas y Geofisicas, UNLP, 1900 La Plata (Argentina) and Instituto de Fisica La Plata, CONICET, 1900 La Plata (Argentina)
Hadronic decays of the tau lepton: Theoretical outlook
The structure of the form factors stemmed from the hadronization of QCD currents in the energy region of the resonances can be explored through the analyses of exclusive hadronic decays of the tau lepton. I give a short review on the later theoretical progress achieved in the description of experimental data.
J. Portoles
Nuclear Chemistry Beta decay of 71,73
34 Nuclear Chemistry Beta decay of 71,73 Co: probing single-parti- cle states approaching doubly of primary interest are the nuclear magnetic dipole moment and nuclear electric quadrupole moment. The dipole/or neutrons in the nucleus. The dipole moment provides information on the nuclear quantum structure
Mantica, Paul F.
Decay Rates for Spherical Scalar Waves in the Schwarzschild Geometry
The Cauchy problem is considered for the scalar wave equation in the Schwarzschild geometry. Using an integral spectral representation we derive the exact decay rate for solutions of the Cauchy problem with spherical symmetric initial data, which is smooth and compactly supported outside the event horizon.
Johann Kronthaler
Search for a light Higgs boson decaying to two gluons or ss? in the radiative decays of ?(1S)
We search for the decay ?(1S)??A[superscript 0], A[superscript 0]?gg or ss? , where A[superscript 0] is the pseudoscalar light Higgs boson predicted by the next-to-minimal supersymmetric Standard Model. We use a sample of ...
Predictability of Precipitation from Continental Radar Images. Part V: Growth and Decay
In a Lagrangian frame of reference, the accuracy of rainfall systems predicted by nowcasting algorithms can be improved by incorporating the growth and decay of the rainfall. The scale dependence of predictability of growth and decay of ...
Basivi Radhakrishna; Isztar Zawadzki; Fr�d�ric Fabry
Estimation of the alpha decay half-lives D. N. Poenaru and M. Ivascu
semiempirical relationship is derived on the grounds of the fission theory of alpha decay. It takes }, based on the fission theory of alpha decay [16] have been derived and was briefly presented in refe
Paris-Sud XI, Université de
Search for Higgs Bosons in SUSY cascade decays and neutralino dark matter.
The minimal supersymmetric extension of the standard model (MSSM) is a well-motivated theoretical framework, which contains an extended Higgs sector, including a light Higgs with standard model-like properties in most of the parameter space. Because of the large QCD background, searches for such a Higgs, decaying into a pair of bottom quarks, are very challenging at the LHC. It has been long realized that the situation may be ameliorated by searching for Higgs bosons in supersymmetric decay chains. Moreover, it has been recently suggested that the b{bar b} decay channel may be observed in standard production channels by selecting boosted Higgs bosons, which may be easily identified from the QCD background. Such boosted Higgs bosons are frequent in the MSSM, since they are produced from decays of heavy colored supersymmetric particles. Previous works have emphasized the possibility of observing boosted Higgs bosons in the light Higgsino region. In this work, we study the same question in the regions of parameter space consistent with a neutralino dark matter relic density, analyzing its dependence on the nonstandard Higgs boson, slepton, and squark masses, as well as on the condition of gaugino mass unification. In general, we conclude that, provided sleptons are heavier than the second lightest neutralinos, the presence of boosted Higgs is a common MSSM feature, implying excellent prospects for observation of the light MSSM Higgs boson in the near future.
Gori, S.; Schwaller, P.; Wagner, C. E. M. (High Energy Physics); (Univ. of Chicago); (Northwestern Univ.); (Univ. of Illinois at Chicago)
{rho} meson decay in 2+1 flavor lattice QCD
We perform a lattice QCD study of the {rho} meson decay from the N{sub f}=2+1 full QCD configurations generated with a renormalization group improved gauge action and a nonperturbatively O(a)-improved Wilson fermion action. The resonance parameters, the effective {rho}{yields}{pi}{pi} coupling constant and the resonance mass, are estimated from the P-wave scattering phase shift for the isospin I=1 two-pion system. The finite size formulas are employed to calculate the phase shift from the energy on the lattice. Our calculations are carried out at two quark masses, m{sub {pi}=}410 MeV (m{sub {pi}/}m{sub {rho}=}0.46) and m{sub {pi}=}300 MeV (m{sub {pi}/}m{sub {rho}=}0.35), on a 32{sup 3}x64 (La=2.9 fm) lattice at the lattice spacing a=0.091 fm. We compare our results at these two quark masses with those given in the previous works using N{sub f}=2 full QCD configurations and the experiment.
Aoki, S.; Ishizuka, N.; Taniguchi, Y.; Ukawa, A.; Yoshie, T. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Ishikawa, K-I.; Okawa, M. [Department of Physics, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8526 (Japan); Kanaya, K. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Kuramashi, Y. [Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan); Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); RIKEN Advanced Institute for Computational Science, Kobe, Hyogo 650-0047 (Japan); Namekawa, Y.; Ukita, N. [Center for Computational Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577 (Japan); Yamazaki, T. [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya, Aichi 464-8602 (Japan)
Non-leptonic decays in an extended chiral quark model
We consider the color suppressed (nonfactorizable) amplitude for the decay mode B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0}. We treat the b-quark in the heavy quark limit and the energetic light (u,d,s) quarks within a variant of Large Energy Effective Theory combined with an extension of chiral quark models. Our calculated amplitude for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} is suppressed by a factor of order {Lambda}{sub QCD}/m{sub b} with respect to the factorized amplitude, as it should according to QCD-factorization. Further, for reasonable values of the (model dependent) gluon condensate and the constituent quark mass, the calculated nonfactorizable amplitude for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0} can easily accomodate the experimental value. Unfortunately, the color suppressed amplitude is very sensitive to the values of these model dependent parameters. Therefore fine-tuning is necessary in order to obtain an amplitude compatible with the experimental result for B{sub d}{sup 0}{yields}{pi}{sup 0}{pi}{sup 0}.
Eeg, J. O. [Dept. of Physics, Univ. of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo (Norway)
Searches for Exotic Decays of the Upsilon(3S) at BaBar
In this paper we present two searches for new physics in {Upsilon}(3S) decays collected by the BABAR detector. We search for charged lepton-flavour violating decays of the {Upsilon}(3S), which are unobservable in the Standard Model but are predicted to occur in several beyond-the-Standard Model scenarios. We also search for production of a light Higgs or Higgs-like state produced in radiative decays of the {Upsilon}(3S) and decaying to muon pairs.
Hooberman, Benjamin; /LBL, Berkeley /Heidelberg U.
Search for the Standard Model Higgs boson in the fully leptonic WW decay channel at CMS
of the Higgs boson . . . . . . . . . . . . . . . . . . . . .the Higgs boson . . . . . . . . . . . . . . . . . . . . . .5 Search for the Higgs Boson in the WW Decay Channel . . .
LeBourgeois, Matthew; LeBourgeois, Matthew
Disentangling the various Mechanisms of neutrinoless double beta decay to extract the neutrino mass
It is well known that there exist many mechanisms that may contribute to neutrinoless double beta decay. By exploiting the fact that the associated nuclear matrix elements are target dependent we show that, given definite experimental results on a sufficient number of targets, one can determine or sufficiently constrain all lepton violating parameters including the mass term. As a specific example we show that, given the observation of the 0{nu}{beta}{beta}-decay in three different nuclei, e.g. {sup 76}Ge, {sup 100}Mo and {sup 130}Te, and assuming just three active lepton number violating parameters, e.g. light and heavy neutrino mass mechanisms in left handed currents as well as R-parity breaking SUSY mechanism, one may determine all lepton violating parameters, provided that they are relatively real.
Vergados, J. D. [Physics Department, University of Ioannina, Ioannina, GR 451 10, Greece and Theory Division, CERN 1211, Geneva 23 (Greece)
HEP/123-qed Fine structure of alpha decay in odd nuclei
Using an ? decay level scheme, the fine structure in odd nuclei is explained by taking into account the radial and rotational couplings between the unpaired valence nucleon and the core of the decaying system. It is shown that the experimental behavior of the ? decay fine structure phenomenon is governed by the dynamical characteristics of the system.
M. Mirea
Evidence for the Decay Sigma+ -> p mu+ mu-
We report the first evidence for the decay Sigma+ -> p mu+ mu- from data taken by the HyperCP experiment(E871) at Fermilab. Based on three observed events, the branching ratio is B(Sigma+ -> p,mu+,mu-) = [8.6 +6.6,-5.4(stat) +/-5.5(syst)] x 10**-8. The narrow range of dimuon masses may indicate that the decay proceeds via a neutral intermediate state, Sigma+ -> p P0, P0 -> mu+ mu-, with a P0 mass of 214.3 +/- 0.5 MeV/c**2 and branching ratio B(Sigma+ -> p P0; P0 -> mu+ mu-) = [3.1 +2.4,-1.(stat) +/-1.5(syst)] x 10**-8.
H. K. Park; R. A. Burnstein; A. Chakravorty; Y. C. Chen; W. S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; H. R. Gustafson; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; T. Jones; D. M. Kaplan; L. M. Lederman; N. Leros; M. J. Longo; F. Lopez; L. C. Lu; W. Luebke; K. B. Luk; K. S. Nelson; J. -P. Perroud; D. Rajaram; H. A. Rubin; J. Volk; C. G. White; S. L. White; P. Zyla
Exactly Solvable Model for the Decay of Superdeformed Nuclei
The history and importance of superdeformation in nuclei is briefly discussed. A simple two-level model is then employed to obtain an elegant expression for the branching ratio for the decay via the E1 process in the normal-deformed band of superdeformed nuclei. From this expression, the spreading width Gamma^downarrow for superdeformed decay is found to be determined completely by experimentally known quantities. The accuracy of the two-level approximation is verified by considering the effects of other normal-deformed states. Furthermore, by using a statistical model of the energy levels in the normal-deformed well, we can obtain a probabilistic expression for the tunneling matrix element V.
B. R. Barrett; D. M. Cardamone; C. A. Stafford
Phenomenology of a leptonic goldstino and invisible Higgs boson decays
Non-linearly realized supersymmetry, combined with the Standard Model field content and SU(3)XSU(2)XU(1) gauge invariance, permits local dimension-six operators involving a goldstino, a lepton doublet and a Higgs doublet. These interactions preserve total lepton number if the left-handed goldstino transforms as an antilepton. We discuss the resulting phenomenology, in the simple limit where the new couplings involve only one lepton family, thus conserving also lepton flavour. Both the Z boson and the Higgs boson can decay into a neutrino and a goldstino: the present limits from the invisible Z width and from other observables leave room for the striking possibility of a Higgs boson decaying dominantly, or at least with a sizable branching ratio, via such an invisible mode. We finally comment on the perspectives at hadron and lepton colliders, and on possible extensions of our analysis.
Ignatios Antoniadis; Marc Tuckmantel; Fabio Zwirner
LSP sneutrino decays into heavy standard model pairs
In bilinear R-parity violation (BRpV), in which the superpotential includes a bilinear term between the lepton doublet and the up-type Higgs superfields, a sneutrino LSP can decay into pairs of heavy standard model states: W's, Z's, tops or Higgs bosons. These finals states can dominate over the traditionally considered bottom pair final state. This would lead to unique and novel supersymmetric signals with each supersymmetric event possibly producing two pairs of these heavy standard model fields. We investigate this possibility and find that the branching ratio into heavier states dominates when the bilinear term is much smaller than the sneutrino vacuum expectation value for a given sneutrino flavor. When BRpV is the only source of neutrino masses these decays can only dominate for one of the sneutrino generations. Relaxing this constraint opens these channels for all three generations.
D. Aristizabal Sierra; D. Restrepo; S. Spinner
Search for Charged Lepton Violation in Narrow Upsilon Decays
Charged lepton flavor violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 x 10{sup 6} {Upsilon}(2S) decays and 117 x 10{sup 6} {Upsilon}(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions {Beta}({Upsilon}(nS) {yields} e{sup {+-}}{tau}{sup {-+}}) and {Beta}({Upsilon}(nS) {yields} {mu}{sup {+-}}{tau}{sup {-+}}) (n = 2, 3) at the 10{sup -6} level and use these results to place lower limits of order 1 TeV on the mass scale of charged lepton flavor violating effective operators.
Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /LBL, Berkeley /UC, Berkeley; Hawkes, C.M.; /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Columbus Supercond., Genova /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Consorzio Milano Ricerche /INFN, Milan /Mississippi U. /Montreal U. /Napoli Seconda U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Perugia U. /INFN, Perugia /INFN, Pisa /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison
Analysis of B ? ?l? Decays With BaBar
As part of the BaBar project at SLAC to study the properties of B mesons, we have carried out a study of the exclusive charmless semileptonic decay mode B ? ?l?, which can be used to determine the magnitude of the Cabbibo- Kobayashi-Maskawa matrix element Vub. Using simulated event samples, this study focuses on determining criteria on variables for selection of B ? ?l? signal and suppression of background from other types of BB events and continuum processes. In addition, we determine optimal cuts on variables to ensure a good neutrino reconstruction. With these selection cuts, we were able to achieve a signal-to-background ratio of 0.68 and a signal efficiency of the order of 1%. Applying these cuts to a sample of 83 million BB events recorded by BaBar in e+e� collisions at the (4S) resonance, we obtain a yield of 115 � 19 B ? ?l? decays.
Chu, Y.; Littlejohn, B.; Binfelder, J.
Branching Fraction Measurement of B to omega l nu decays
We present a measurement of the B{sup +} {yields} {omega}{ell}{sup +}{nu} branching fraction based on a sample of 467 million B{bar B} pairs recorded by the BABAR detector at the SLAC PEP-II e{sup +}e{sup -} collider. We observe 1041 {+-} 133 signal decays, corresponding to a branching fraction of {Beta}(B{sup +} {yields} {omega}{ell}{sup +}{nu}) = (1.15 {+-} 0.15 {+-} 0.12) x 10{sup -4}, where the first error is statistical and the second is systematic. The dependence of the decay rate on q{sup 2}, the momentum transfer squared to the lepton system, is compared to QCD predictions of the form factors based on a quark model and light-cone sum rules.
Lees, J.P.; Poireau, V.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Palano, A.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /LBL, Berkeley /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; So, R.Y.; /British Columbia U.; Khan, A.; /Brunel U.; Blinov, V.E.; /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U., Comp. Sci. Dept. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U.; /more authors..
Microscopic description of complex nuclear decay: multimodal fission
Our understanding of nuclear fission, a fundamental nuclear decay, is still incomplete due to the complexity of the process. In this paper, we describe a study of spontaneous fission using the symmetry-unrestricted nuclear density functional theory. Our results show that the observed bimodal fission can be explained in terms of pathways in multidimensional collective space corresponding to different geometries of fission products. We also predict a new phenomenon of trimodal spontaneous fission for some rutherfordium, seaborgium, and hassium isotopes.
A. Staszczak; A. Baran; J. Dobaczewski; W. Nazarewicz
Observation of New Charmless Decays of Bottom Hadrons
The authors search for new charmless decays of neutral b-hadrons to pairs of charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 1 fb{sup -1} of integrated luminosity, they report the first observation of the B{sub s}{sup 0} {yields} K{sup +}{pi}{sup +} decay, with a significance of 8.2{sigma}, and measure {Beta}(B{sub s}{sup 0} {yields} K{sup -}{pi}{sup +}) = (5.0 {+-} 0.7 (stat.) {+-} 0.8 (syst.)) x 10{sup -6}. They also report the first observation of charmless b-baryon decays in the channels {Lambda}{sub b}{sup 0} {yields} p{pi}{sup -} and {Lambda}{sub b}{sup 0} {yields} pK{sup -} with significances of 6.0{sigma} and 11.5{sigma} respectively, and they measure {Beta}({Lambda}{sub b}{sup 0} {yields} p{pi}{sup -}) = (3.5 {+-} 0.6 (stat.) {+-} 0.9 (syst.)) x 10{sup -6} and {Beta}({Lambda}{sub b}{sup 0} {yields} pK{sup -}) = (5.6 {+-} 0.8 (stat.) {+-} 1.5 (syst.)) x 10{sup -6}. No evidence is found for the decays B{sup 0} {yields} K{sup +}K{sup -} and B{sub s}{sup 0} {yields} {pi}{sup +}{pi}{sup -}, and they set an improved upper limit {Beta}(B{sub s}{sup 0} {yields} {pi}{sup +}{pi}{sup -}) < 1.2 x 10{sup -6} at the 90% confidence level. All quoted branching fractions are measured using {Beta}(B{sup 0} {yields} K{sup +}{pi}{sup -}) as a reference.
Morello, Michael J.; /Fermilab
Search for the Lepton-Number-Violating Decay $?^- \\to p ?^- ?^-$
A sensitive search for the lepton-number-violating decay $\\Xi^-\\to p \\mu^-\\mu^-$ has been performed using a sample of $\\sim10^9$ $\\Xi^-$ hyperons produced in 800 GeV/$c$ $p$-Cu collisions. We obtain $\\mathcal{B}(\\Xi^-\\to p \\mu^-\\mu^-)< 4.0\\times 10^{-8}$ at 90% confidence, improving on the best previous limit by four orders of magnitude.
HyperCP Collaboration; D. Rajaram; R. A. Burnstein; A. Chakravorty; Y. C. Chen; W. -S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; H. R. Gustafson; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; T. D. Jones; D. M. Kaplan; M. J. Longo; L. C. Lu; W. Luebke; K. -B. Luk; K. S. Nelson; H. K. Park; J. -P. Perroud; H. A. Rubin; J. Volk; C. G. White; S. L. White; P. Zyla
Study of the D 0 ?? + ? ? ? 0 decay at BABAR
The Dalitz?plot of the decay D 0 ?? + ? ? ? 0 measured by the BABAR collaboration shows the structure of a final state having quantum numbers I G J PC ?=?0 ? 0 ?? . An isospin analysis of this Dalitz?plot finds that the fraction of the I?=?0 contribution is about 96%. This high I?=?0 contribution is unexpected because the weak interaction violates the isospin.
Mario Gaspero; The BABAR Collaboration
Higgs Boson Decays into Single Photon plus Unparticle
The decay of the standard model Higgs boson into a single photon and a vector unparticle through a one-loop process is studied. For an intermediate mass Higgs boson, this single photon plus unparticle mode can have a branching ratio comparable with the two-photon discovery mode. The emitted photon has a continuous energy spectrum encoding the nature of the recoil unparticle. It can be measured in precision studies of the Higgs boson after its discovery.
Kingman Cheung; Chong Sheng Li; Tzu-Chiang Yuan
Search for the rare decays Bs -->mumu and Bd -->mumu
A search for the decays Bs-->mumu and Bd-->mumu is performed with about 37 pb^{-1} of pp collisions at sqrt{s} = 7 TeV collected by the LHCb experiment at the Large Hadron Collider at CERN. The observed numbers of events are consistent with the background expectations. The resulting upper limits on the branching ratios are BR(Bs-->mumu) mumu) <1.5 x 10^{-8} at 95% confidence level.
LHCb Collaboration; R. Aaij; B. Adeva; M. Adinolfi; C. Adrover; A. Affolder; Z. Ajaltouni; J. Albrecht; F. Alessio; M. Alexander; P. Alvarez Cartelle; A. A. Alves Jr; S. Amato; Y. Amhis; J. Amoraal; J. Anderson; R. B. Appleby; O. Aquines Gutierrez; L. Arrabito; M. Artuso; E. Aslanides; G. Auriemma; S. Bachmann; D. S. Bailey; V. Balagura; W. Baldini; R. J. Barlow; C. Barschel; S. Barsuk; A. Bates; C. Bauer; Th. Bauer; A. Bay; I. Bediaga; K. Belous; I. Belyaev; E. Ben-Haim; M. Benayoun; G. Bencivenni; R. Bernet; M. -O. Bettler; M. van Beuzekom; A. Bien; S. Bifani; A. Bizzeti; P. M. Bj�rnstad; T. Blake; F. Blanc; C. Blanks; J. Blouw; S. Blusk; A. Bobrov; V. Bocci; A. Bondar; N. Bondar; W. Bonivento; S. Borghi; A. Borgia; E. Bos; T. J. V. Bowcock; C. Bozzi; T. Brambach; J. van den Brand; J. Bressieux; S. Brisbane; M. Britsch; T. Britton; N. H. Brook; H. Brown; A. B�chler-Germann; A. Bursche; J. Buytaert; S. Cadeddu; J. M. Caicedo Carvajal; O. Callot; M. Calvi; M. Calvo Gomez; A. Camboni; P. Campana; A. Carbone; G. Carboni; R. Cardinale; A. Cardini; L. Carson; K. Carvalho Akiba; G. Casse; M. Cattaneo; M. Charles; Ph. Charpentier; N. Chiapolini; X. Cid Vidal; P. J. Clark; P. E. L. Clarke; M. Clemencic; H. V. Cliff; J. Closier; C. Coca; V. Coco; J. Cogan; P. Collins; F. Constantin; G. Conti; A. Contu; M. Coombes; G. Corti; G. A. Cowan; R. Currie; B. D'Almagne; C. D'Ambrosio; W. Da Silva; P. David; I. De Bonis; S. De Capua; M. De Cian; F. De Lorenzi; J. M. De Miranda; L. De Paula; P. De Simone; D. Decamp; H. Degaudenzi; M. Deissenroth; L. Del Buono; C. Deplano; O. Deschamps; F. Dettori; J. Dickens; H. Dijkstra; M. Dima; P. Diniz Batista; S. Donleavy; D. Dossett; A. Dovbnya; F. Dupertuis; R. Dzhelyadin; C. Eames; S. Easo; U. Egede; V. Egorychev; S. Eidelman; D. van Eijk; F. Eisele; S. Eisenhardt; L. Eklund; Ch. Elsasser; D. G. d'Enterria; D. Esperante Pereira; L. Est�ve; A. Falabella; E. Fanchini; C. F�rber; G. Fardell; C. Farinelli; S. Farry; V. Fave; V. Fernandez Albor; M. Ferro-Luzzi; S. Filippov; C. Fitzpatrick; F. Fontanelli; R. Forty; M. Frank; C. Frei; M. Frosini; S. Furcas; A. Gallas Torreira; D. Galli; M. Gandelman; P. Gandini; Y. Gao; J-C. Garnier; J. Garofoli; L. Garrido; C. Gaspar; N. Gauvin; M. Gersabeck; T. Gershon; Ph. Ghez; V. Gibson; V. V. Gligorov; C. G�bel; D. Golubkov; A. Golutvin; A. Gomes; H. Gordon; M. Grabalosa G�ndara; R. Graciani Diaz; L. A. Granado Cardoso; E. Graug�s; G. Graziani; A. Grecu; S. Gregson; B. Gui; E. Gushchin; Yu. Guz; T. Gys; G. Haefeli; S. C. Haines; T. Hampson; S. Hansmann-Menzemer; R. Harji; N. Harnew; P. F. Harrison; J. He; K. Hennessy; P. Henrard; J. A. Hernando Morata; E. van Herwijnen; A. Hicheur; E. Hicks; W. Hofmann; K. Holubyev; P. Hopchev; W. Hulsbergen; P. Hunt; T. Huse; R. S. Huston; D. Hutchcroft; V. Iakovenko; P. Ilten; J. Imong; R. Jacobsson; M. Jahjah Hussein; E. Jans; F. Jansen; P. Jaton; B. Jean-Marie; F. Jing; M. John; D. Johnson; C. R. Jones; B. Jost; F. Kapusta; T. M. Karbach; J. Keaveney; U. Kerzel; T. Ketel; A. Keune; B. Khanji; Y. M. Kim; M. Knecht; S. Koblitz; A. Konoplyannikov; P. Koppenburg; A. Kozlinskiy; L. Kravchuk; G. Krocker; P. Krokovny; F. Kruse; K. Kruzelecki; M. Kucharczyk; S. Kukulak; R. Kumar; T. Kvaratskheliya; V. N. La Thi; D. Lacarrere; G. Lafferty; A. Lai; R. W. Lambert; G. Lanfranchi; C. Langenbruch; T. Latham; R. Le Gac; J. van Leerdam; J. -P. Lees; R. Lef�vre; A. Leflat; J. Lefran�ois; O. Leroy; T. Lesiak; L. Li; Y. Y. Li; L. Li Gioi; M. Lieng; M. Liles; R. Lindner; C. Linn; B. Liu; G. Liu; J. H. Lopes; E. Lopez Asamar; N. Lopez-March; J. Luisier; B. M'charek; F. Machefert; I. V. Machikhiliyan; F. Maciuc; O. Maev; J. Magnin; A. Maier; S. Malde; R. M. D. Mamunur; G. Manca; G. Mancinelli; N. Mangiafave; U. Marconi; R. M�rki; J. Marks; G. Martellotti; A. Martens; L. Martin; A. Mart�n S�nchez; D. Martinez Santos; A. Massafferri; Z. Mathe; C. Matteuzzi; M. Matveev; V. Matveev; E. Maurice; B. Maynard; A. Mazurov; G. McGregor; R. McNulty; C. Mclean; M. Meissner; M. Merk; J. Merkel; M. Merkin; R. Messi; S. Miglioranzi; D. A. Milanes; M. -N. Minard; S. Monteil; D. Moran; P. Morawski; J. V. Morris; R. Mountain; I. Mous; F. Muheim; K. M�ller; R. Muresan; F. Murtas; B. Muryn; M. Musy; J. Mylroie-Smith; P. Naik; T. Nakada; R. Nandakumar; J. Nardulli; M. Nedos; M. Needham; N. Neufeld; M. Nicol; S. Nies; V. Niess; N. Nikitin; A. Oblakowska-Mucha; V. Obraztsov; S. Oggero; O. Okhrimenko; R. Oldeman; M. Orlandea; A. Ostankov; B. Pal; J. Palacios; M. Palutan; J. Panman; A. Papanestis; M. Pappagallo; C. Parkes; C. J. Parkinson; G. Passaleva; G. D. Patel; M. Patel; S. K. Paterson; G. N. Patrick; C. Patrignani; C. Pavel -Nicorescu; A. Pazos Alvarez; A. Pellegrino; G. Penso; M. Pepe Altarelli; S. Perazzini; D. L. Perego; E. Perez Trigo; A. P�rez-Calero Yzquierdo; P. Perret; A. Petrella
Numerical simulations of the decay of primordial magnetic turbulence
We perform direct numerical simulations of forced and freely decaying 3D magnetohydrodynamic turbulence in order to model magnetic field evolution during cosmological phase transitions in the early Universe. Our approach assumes the existence of a magnetic field generated either by a process during inflation or shortly thereafter, or by bubble collisions during a phase transition. We show that the final configuration of the magnetic field depends on the initial conditions, while the velocity field is nearly independent of initial conditions.
Kahniashvili, Tina [McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Department of Physics, Laurentian University, Ramsey Lake Road, Sudbury, ON P3E 2C (Canada); Abastumani Astrophysical Observatory, Ilia State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia); Brandenburg, Axel [Nordita, AlbaNova University Center, Roslagstullsbacken 23, 10691 Stockholm (Sweden); Department of Astronomy, Stockholm University, SE 10691 Stockholm (Sweden); Tevzadze, Alexander G. [Abastumani Astrophysical Observatory, Ilia State University, 2A Kazbegi Ave, Tbilisi, GE-0160 (Georgia); Faculty of Exact and Natural Sciences, Tbilisi State University, 1 Chavchavadze Avenue Tbilisi, GE-0128 (Georgia); Ratra, Bharat [Department of Physics, Kansas State University, 116 Cardwell Hall, Manhattan, Kansas 66506 (United States)
Higgs decay to bottom quarks at the Tevatron
We study the production and detection of the standard-model Higgs boson at the Fermilab Tevatron. The most promising mode is WH and ZH associated production followed by leptonic decay of the weak vector bosons and H {yields} b{bar b}. It may be possible to detect a Higgs boson of mass m{sub H} = 60--80 GeV with 1000 pb{sup {minus}1} of integrated luminosity.
Stange, A.; Marciano, W. [Brookhaven National Lab., Upton, NY (United States); Willenbrock, S. [Fermi National Accelerator Lab., Batavia, IL (United States)]|[Brookhaven National Lab., Upton, NY (United States)
Constraining Light Bosons with Radiative $?(1S)$ Decays
Light bosons can be found in large classes of theories beyond the Standard Model. These light bosons may not be ruled out by current experiments and, indeed, may even provide an explanation for some anomalous experimental results. The radiative decays of quarkonium ($c \\bar c, b \\bar b$) states offer a promising opportunity to investigate such light bosons. Specifically, we investigate the reach that current CLEO data can have on models with light scalar and pseudoscalar bosons.
David McKeen
Electroweak Penguin and Leptonic Decays at BaBar
Recent BABAR results on electroweak penguin and leptonic decays are reviewed. In particular, the measurements of B {yields} K{sup (*)}l{sup +}l{sup -} and the preliminary results on B {yields} X{sub s}l{sup +}l{sup -} are presented. Also summarized are the preliminary limits on B{sup +} {yields} l{sup +}{nu} (l = e,{mu}) and B{sup +} {yields} K{sup +}{nu}{bar {nu}}.
Bucci, F.; /Pisa U. /INFN, Pisa
Effects of light scalar mesons in $\\eta \\to 3\\pi$ decay
We study the role of a possible nonet of light scalar mesons in the still interesting $\\eta \\to 3\\pi$ decay process, with the primary motivation of learning more about the scalars themselves. The framework is a conventional non-linear chiral Lagrangian of pseudoscalars and vectors, extended to include the scalars. The parameters involving the scalars were previously obtained to fit the s-wave $\\pi\\pi$ and $\\pi$K scatterings in the region up to about 1 GeV as well as the strong decay $\\eta' \\to \\eta \\pi\\pi$. At first, one might expect a large enhancement from diagrams including a light $\\sigma(560)$. However there is an amusing cancellation mechanism which prevents this from occurring. In the simplest model there is an enhancement of about 13 per cent in the \\e3p decay rate due to the scalars. In a more complicated model which includes derivative type symmetry breakers, the cancellation is modified and the scalars contribute about 30 percent of the total decay rate (although the total is not significantly chan...
Abdel-Rehim, A M; Fariborz, A H; Schechter, J; Abdel-Rehim, Abdou M.; Black, Deirdre; Fariborz, Amir H.; Schechter, Joseph
Solar Influence on Nuclear Decay Rates: Constraints from the MESSENGER Mission
We have analyzed Cs-137 decay data, obtained from a small sample onboard the MESSENGER spacecraft en route to Mercury, with the aim of setting limits on a possible correlation between nuclear decay rates and solar activity. Such a correlation has been suggested recently on the basis of data from Mn-54 decay during the solar flare of 13 December 2006, and by indications of an annual and other periodic variations in the decay rates of Si-32, Cl-36, and Ra-226. Data from five measurements of the Cs-137 count rate over a period of approximately 5.4 years have been fit to a formula which accounts for the usual exponential decrease in count rate over time, along with the addition of a theoretical solar contribution varying with MESSENGER-Sun separation. The indication of solar influence is then characterized by a non-zero value of the calculated parameter \\xi, and we find \\xi=(2.8+/-8.1)x10^{-3} for Cs-137. A simulation of the increased data that can hypothetically be expected following Mercury orbit insertion on 18 March 2011 suggests that the anticipated improvement in the determination of \\xi could reveal a non-zero value of \\xi if present at a level consistent with other data.
Ephraim Fischbach; K. Joseph Chen; Robert E. Gold; John O. Goldsten; David J. Lawrence; Ralph J. McNutt Jr.; Edgar A. Rhodes; Jere H. Jenkins; James M. Longuski
Novel Higgs-to-125 GeV Higgs boson decays in the complex NMSSM
In the Next-to-Minimal Supersymmetric Standard Model (NMSSM) a variety of parameter configurations yields a Higgs boson consistent with the one observed at the LHC. Additionally, the Higgs sector of the model can contain explicit CP-violating phases even at the tree level, in contrast with the Minimal Supersymmetric Standard Model (MSSM). In this article we present the complete one-loop Higgs boson mass matrix of the complex NMSSM in the renormalisation-group improved effective potential approach. We also present the trilinear Higgs boson self-couplings and the complete set of expressions for various partial decay widths of a generic CP-mixed Higgs boson in the model. We then analyse a very interesting phenomenological scenario wherein the decay of a relatively light pseudoscalar-like Higgs boson into ~ 125 GeV SM-like Higgs boson(s) is induced by non-zero CP-violating phases. We discuss in detail a few benchmark cases in which such a decay can contribute significantly to the production of SM-like Higgs bosons at the LHC on top of the gluon fusion process. It can thus be partially responsible for the gamma.gamma excess near 125 GeV due to the subsequent decay of the SM-like Higgs boson. Such a scenario is extremely difficult to realize in the complex MSSM and, if probed at the LHC, it could provide an indication of the non-minimal nature of supersymmetry.
Shoaib Munir
FORM FACTORS FOR RADIATIVE PION AND KAON DECAYS Updated August
August August 2009 by W. Bertl (Paul Scherrer Inst.) The radiative decays, π ± → l ± νγ and K ± → l ± νγ, with l standing for an e or a µ, and γ for a real or virtual photon (e + e - pair), provide a powerful tool to investigate the hadronic structure of pions and kaons. The structure-dependent part SD i of the amplitude describes the emission of photons from virtual hadronic states, and is parametrized in terms of form factors F i , with i = V, A (vector, axial vector), in the standard description [1,2]. Exotic, non-standard contributions like i = T, S (tensor, scalar) have also been considered, and we shall discuss them below. Apart from the SD terms, the decay amplitude depends also on Inner Bremsstrahlung IB from the weak decay π ± (K ± ) → l ± ν accompanied by the photon radiated from the external charged particles. Naturally, experiments try to optimize their kinematics so as to minimize
A New Measurement of the $?^0$ Radiative Decay Width
High precision measurements of the differential cross sections for $\\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\\pi^0 \\to \\gamma\\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The ${\\pi^0 \\to \\gamma\\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\\Gamma{(\\pi^0 \\to \\gamma\\gamma)} = 7.82 \\pm 0.14 ~({\\rm stat.}) \\pm 0.17 ~({\\rm syst.}) ~{\\rm eV}$. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions.
I. Larin; D. McNulty; E. Clinton; P. Ambrozewicz; D. Lawrence; I. Nakagawa; Y. Prok; A. Teymurazyan; A. Ahmidouch; A. Asratyan; K. Baker; L. Benton; A. M. Bernstein; V. Burkert; P. Cole; P. Collins; D. Dale; S. Danagoulian; G. Davidenko; R. Demirchyan; A. Deur; A. Dolgolenko; G. Dzyubenko; R. Ent; A. Evdokimov; J. Feng; M. Gabrielyan; L. Gan; A. Gasparian; S. Gevorkyan; A. Glamazdin; V. Goryachev; V. Gyurjyan; K. Hardy; J. He; M. Ito; L. Jiang; D. Kashy; M. Khandaker; P. Kingsberry; A. Kolarkar; M. Konchatnyi; A. Korchin; W. Korsch; S. Kowalski; M. Kubantsev; V. Kubarovsky; X. Li; P. Martel; V. Matveev; B. Mecking; B. Milbrath; R. Minehart; R. Miskimen; V. Mochalov; S. Mtingwa; S. Overby; E. Pasyuk; M. Payen; R. Pedroni; B. Ritchie; T. E. Rodrigues; C. Salgado; A. Shahinyan; A. Sitnikov; D. Sober; S. Stepanyan; W. Stephens; J. Underwood; A. Vasiliev; V. Vishnyakov; M. Wood; S. Zhou
Study of the rare hyperon decay Omega \\to Xi ?^+ ?^-
We report a new measurement of the decay \\Omega^- \\to \\Xi^- \\pi^+ \\pi^- with 76 events and a first observation of the decay \\Omega^+ \\to \\Xi^+ \\pi^+ \\pi^- with 24 events, yielding a combined branching ratio (3.74 ^{+0.67}_{-0.56}) \\times 10^{-4}. This represents a factor 25 increase in statistics over the best previous measurement. No evidence is seen for CP violation, with B(\\Omega^- \\to \\Xi^- \\pi^+ \\pi^-)=4.04^{+0.83}_{-0.71} \\times 10^{-4} and B(\\Omega^+ \\to \\Xi^+ \\pi^+ \\pi^-)=3.15^{+1.12}_{-0.89} \\times 10^{-4}. Contrary to theoretical expectation, we see little evidence for the decays \\Omega^- \\to \\Xi_{1530}^{*0} \\pi^- and \\Omega^+ \\to \\Xi_{1530}^{*0} \\pi^+ and place a 90% C.L. upper limit on the combined branching ratio B(\\Omega^-(\\Omega^+) \\to \\Xi^{*0}_{1530}(\\Xi^{*0}_{1530}) \\pi^\\mp)<7.0 \\times 10^{-5}.
HyperCP Collaboration; O. Kamaev; N. Solomey; R. A. Burnstein; A. Chakravorty; Y. C. Chen; W. -S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; H. R. Gustafson; T. Holmstrom; M. Huang; C. James; C. M. Jenkins; T. D. Jones; D. M. Kaplan; M. J. Longo; L. C. Lu; W. Luebke; K. -B. Luk; K. S. Nelson; H. K. Park; J. -P. Perroud; D. Rajaram; H. A. Rubin; J. Volk; C. G. White; S. L. White; P. Zyla
Concerning the Phases of Annual Variations of Nuclear Decay Rates
Recent analyses of datasets acquired at the Brookhaven National Laboratory and at the Physikalisch-Technische Bundesanstalt both show evidence of pronounced annual variations, suggestive of a solar influence. However, the phases of decay-rate maxima do not correspond precisely to the phase of minimum Sun-Earth distance, as might then be expected. We here examine the hypothesis that decay rates are influenced by an unknown solar radiation, but that the intensity of the radiation is influenced not only by the variation in Sun-Earth distance, but also by a possible North-South asymmetry in the solar emission mechanism. We find that this can lead to phases of decay-rate maxima in the range 0 to 0.183 or 0.683 to 1 (September 6 to March 8) but that, according to this hypothesis, phases in the range 0.183 to 0.683 (March 8 to September 6) are "forbidden." We find that phases of the three datasets here analyzed fall in the allowed range.
Peter A. Sturrock; John B. Buncher; Ephraim Fischbach; Daniel Javorsek II; Jere H. Jenkins; Joshua J. Mattes
Nuclear decay data files of the Dosimetry Research Group
This report documents the nuclear decay data files used by the Dosimetry Research Group at Oak Ridge National Laboratory and the utility DEXRAX which provides access to the files. The files are accessed, by nuclide, to extract information on the intensities and energies of the radiations associated with spontaneous nuclear transformation of the radionuclides. In addition, beta spectral data are available for all beta-emitting nuclides. Two collections of nuclear decay data are discussed. The larger collection contains data for 838 radionuclides, which includes the 825 radionuclides assembled during the preparation of Publications 30 and 38 of the International Commission on Radiological Protection (ICRP) and 13 additional nuclides evaluated in preparing a monograph for the Medical Internal Radiation Dose (MIRD) Committee of the Society of Nuclear Medicine. The second collection is composed of data from the MIRD monograph and contains information for 242 radionuclides. Abridged tabulations of these data have been published by the ICRP in Publication 38 and by the Society of Nuclear Medicine in a monograph entitled ``MIRD: Radionuclide Data and Decay Schemes.`` The beta spectral data reported here have not been published by either organization. Electronic copies of the files and the utility, along with this report, are available from the Radiation Shielding Information Center at Oak Ridge National Laboratory.
Eckerman, K.F.; Westfall, R.J.; Ryman, J.C.; Cristy, M.
Analysis of decay heat removal capabilities at Susquehanna
Since the Susquehanna station began operating in 1982, the Nuclear Safety Assessment Group (NSAG) has conducted independent outage safety reviews. In 1990, NSAG published The Outage Planning Information document which consolidated some of the knowledge gained during the outage safety review process. The report discusses the requirements in the technical specifications and it analyzes the decay heat removal problem during the various stages of an outage. The appendices contain facts concerning decay heat generation and the capabilities of the decay heat removal systems. To the maximum extent possible, design documents and certified test data have been used to establish the capabilities of the systems. The Susquehanna station has two General Electric (GE) boiling water reactors (BWR)-4 GE BWR-4 reactors with Mark-2 containments. The safety systems are composed of two independent divisions. The possible heat sinks are the cooling towers via the circulating water and service water systems, the spray pond via the residual heat removal systems, and the atmosphere via boiling.
Miltenberger, J.R. (Pennsylvania Power and Light Co., Allentown (United States)); Henry, R.A. (Pennsylvania Power and Light Co., Berwick (United States))
The Effect of Vector Meson Decays on Dihadron Fragmentation Functions
Dihadron Fragmentation Functions (DFF) provide a vast amount of information on the intricate details of the parton hadronization process. Moreover, they provide a unique access to the "clean" extraction of nucleon transversity parton distribution functions in semi inclusive deep inelastic two hadron production process with a transversely polarised target. On the example of the u \\to \\pi^+ \\pi^-, we analyse the properties of unpolarised DFFs using their probabilistic interpretation. We use both the NJL-jet hadronization model and PYTHIA 8.1 event generator to explore the effect of the strong decays of the vector mesons produced in the quark hadronization process on the pseudoscalar DFFs. Our study shows that, even though it is less probable to produce vector mesons in the hadronization process than pseudo scalar mesons of the same charge, the products of their strong decays drastically affect the DFFs for pions because of the large combinatorial factors. Thus, an accurate description of both vector meson production and decays are crucial for theoretical understanding of DFFs.
Hrayr H. Matevosyan; Anthony W. Thomas; Wolfgang Bentz
Search for T violation in charm meson decays
Using data from the FOCUS (E831) experiment, they have searched for T violation in charm meson decays using the four-body decay channels D{sup 0} {yields} K{sup -}K{sup +} {pi}{sup -}{pi}{sup +}, D{sup +} {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}{pi}{sup +}, and D{sub s}{sup +} {yields} K{sub S}{sup 0}K{sup +}{pi}{sup -}{pi}{sup +}. The T violation asymmetry is obtained using triple-product correlations and assuming the validity of the CPT theorem. They find the asymmetry values to be A{sub T{sub viol}}(D{sup 0}) = 0.010 {+-} 0.057(stat.) {+-} 0.037(syst.), A{sub T{sub viol}}(D{sup +}) = 0.023 {+-} 0.062(stat.) {+-} 0.022(syst.), and A{sub T{sub viol}}(D{sub s}{sup +}) = -0.036 {+-} 0.067(stat.) {+-} 0.023(syst.). Each measurement is consistent with no T violation. New measurements of the CP asymmetries for some of these decay modes are also presented.
Link, J.M.; Yager, P.M.; /UC, Davis; Anjos, J.C.; Bediaga, I.; Castromonte, C.; Machado, A.A.; Magnin, J.; Massafferri, A.; de Miranda, J.M.; Pepe, I.M.; Polycarpo, E.; dos Reis, A.C.; /Rio de Janeiro, CBPF; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; /CINVESTAV, IPN; Agostino, L.; Cinquini, L.; Cumalat, J.P.; /Colorado U. /Fermilab /Frascati /Guanajuato U. /Illinois U., Urbana /Indiana U. /Korea U. /Kyungpook Natl. U. /INFN, Milan /Milan U. /North Carolina U. /Pavia U. /INFN, Pavia /Rio de Janeiro, Pont. U. Catol. /Puerto Rico U., Mayaguez /South Carolina U. /Tennessee U. /Vanderbilt U. /Wisconsin U., Madison
Precise Measurement of the K - to Pi -E E- Decay
A sample of 7253 K{sup {+-}} {yields} {pi}{sup {+-}}e{sup +}e{sup -}({gamma}) decay candidates with 1.0% background contamination has been collected by the NA 48/2 experiment at the CERN SPS, which allowed a precise measurement of the decay properties. The branching ratio in the full kinematic range was measured to be BR = (3.11 {+-} 0.12) x 10{sup -7}, where the uncertainty includes also the model dependence. The shape of the form factor W(z), where z = (M{sub ee}/M{sub K}){sup 2}, was parameterized according to several models, and, in particular, the slope {delta} of the linear form factor W(z) = W{sub 0}(1 + {delta}z) was determined to be {delta} = 2.32 {+-} 0.18. A possible CP violating asymmetry of K{sup +} and K{sup -} decay widths was investigated, and a conservative upper limit of 2.1 x 10{sup -2} at 90% CL was established.
Batley, J.R.; Culling, A.J.; Kalmus, G.; /Cambridge U.; Lazzeroni, C.; /Cambridge U. /Birmingham U.; Munday, D.J.; /Cambridge U.; Slater, M.W.; /Cambridge U. /Birmingham U.; Wotton, S.A.; /Cambridge U.; Arcidiacono, R.; /CERN /Turin U. /INFN, Turin; Bocquet, G.; /CERN; Cabibbo, N.; /CERN /Rome U. /INFN, Rome; Ceccucci, A.; /CERN; Cundy, D.; /CERN /Turin, Cosmo-Geofisica Lab; Falaleev, V.; Fidecaro, M.; Gatignon, L.; Gonidec, A.; Kubischta, W.; /CERN; Norton, A.; /CERN /Ferrara U. /INFN, Ferrara; Maier, A.; Patel, M.; Peters, A.; /CERN /Dubna, JINR /Pisa, Scuola Normale Superiore /Dubna, JINR /Dubna, JINR /Birmingham U. /Dubna, JINR /CERN /Dubna, JINR /Dubna, JINR /Sofiya U. /Dubna, JINR /Dubna, JINR /INFN, Perugia /Dubna, JINR /Dubna, JINR /Northwestern U. /Dubna, JINR /Chicago U., EFI /Marseille, CPPM /Chicago U., EFI /Edinburgh U. /George Mason U. /Edinburgh U. /Ferrara U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /CERN /Ferrara U. /INFN, Ferrara /Florence U. /INFN, Florence /Modena U. /Florence U. /INFN, Florence /Florence U. /INFN, Florence /Urbino U. /Florence U. /INFN, Florence /Pisa, Scuola Normale Superiore /Florence U. /INFN, Florence /Urbino U. /Mainz U., Inst. Phys. /Mainz U., Inst. Phys. /Bonn U. /Mainz U., Inst. Phys. /Northwestern U. /SLAC /Northwestern U. /Northwestern U. /Royal Holloway, U. of London /Northwestern U. /Northwestern U. /UCLA /Perugia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Frascati /Perugia U. /INFN, Perugia /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa U. /INFN, Pisa /Barcelona, IFAE /Pisa U. /INFN, Pisa /DAPNIA, Saclay /DAPNIA, Saclay /CERN /DAPNIA, Saclay /Siegen U. /Turin U. /INFN, Turin /Bern U. /Turin U. /INFN, Turin /Turin U. /INFN, Turin /CERN /Turin U. /INFN, Turin /Madrid, CIEMAT /Turin U. /INFN, Turin /Vienna, OAW
If a component of cosmological dark matter is made up of massive particles-such as sterile neutrinos-that decay with cosmological lifetime to emit photons, the reionization history of the universe would be affected, and cosmic microwave background anisotropies can be used to constrain such a decaying particle model of dark matter. The optical depth depends rather sensitively on the decaying dark matter particle mass m{sub dm}, lifetime {tau}{sub dm}, and the mass fraction of cold dark matter f that they account for in this model. Assuming that there are no other sources of reionization and using the Wilkinson Microwave Anisotropy Probe 7-year data, we find that 250 eV {approx}< m{sub dm} {approx}< 1 MeV, whereas 2.23 Multiplication-Sign 10{sup 3} yr {approx}< {tau}{sub dm}/f {approx}< 1.23 Multiplication-Sign 10{sup 18} yr. The best-fit values for m{sub dm} and {tau}{sub dm}/f are 17.3 keV and 2.03 Multiplication-Sign 10{sup 16} yr, respectively.
Yeung, S.; Chan, M. H.; Chu, M.-C., E-mail: email@example.com [Department of Physics and Institute of Theoretical Physics, Chinese University of Hong Kong, Shatin, New Territories (Hong Kong)
Some Comments on the Decays of eta (550)
DOE R&D Accomplishments (OSTI)
Various decay modes of the {eta}(500) are discussed. The relations, through SU{sub 3} and the Gell-Mann, Sharp, Wagner model, between the {eta}-decay modes and the modes {eta} {yields} {pi}{pi}{gamma), {pi}{sup 0} {yields} {gamma}{gamma} are investigated taking into account {eta}-{eta}{sup *} mixing. The present experimental values for the neutral branching ratios plus the shape of the {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} Dalitz plot are shown to require a 25% {vert_bar}{Delta}{rvec I}{vert_bar} = 3 contribution to the {eta} {yields} 3{pi} amplitude. The connection between a possible charge asymmetry in {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} and the branching ratio {Gamma}{sub {eta} {yields} {pi}{sup 0}e{sup +}e{sup {minus}}}/{Gamma}{sub {eta}}{sup all} is investigated in the framework of a model proposed earlier by several authors. It is shown that there is no conflict between the existing data and this model. The Dalitz plot distribution of {eta} {yields} {pi}{sup +}{pi}{sup {minus}}{pi}{sup 0} is discussed under various assumptions about the properties of the interaction responsible for the decay. (auth)
Veltman, M.; Yellin, J.
Local decay of waves on asymptotically flat stationary space-times
In this article we study the pointwise decay properties of solutions to the wave equation on a class of stationary asymptotically flat backgrounds in three space dimensions. Under the assumption that uniform energy bounds and a weak form of local energy decay hold forward in time we establish a $t^{-3}$ local uniform decay rate for linear waves. This work was motivated by open problems concerning decay rates for linear waves on Schwarzschild and Kerr backgrounds, where such a decay rate has been conjectured by R. Price. Our results apply to both of these cases.
Tataru, Daniel
Daniel Tataru
$\\rho-\\omega-$Interference in $J/\\psi-$Decays and $\\rho\\to \\pi^+\\pi^-\\pi^0$ Decay
We study $\\rho-\\omega-$interference by analyzing $J/\\psi\\to \\pi^+\\pi^-\\pi^0\\pi^0$. PDG-2002 data on $J/\\psi$ decays into $PP$ and $PV$ ($P$ denotes pseudoscalar mesons; $V$, vector mesons) are used to fit a generic model which describes the $J/\\psi$ decays. From the fits, we obtain anomalously large branching ratio $Br(\\rho^0\\to \\pi^+\\pi^-\\pi^0)\\sim 10^{-3}-10^{-2}$. A theoretical analysis for it is also provided, and the prediction is in good agreement with the anomalously large $Br(\\rho^0\\to \\pi^+\\pi^-\\pi^0)$. By the fit, we also get the $\\eta-\\eta'-$mixing angle $\\theta=-19.68^o\\pm 1.49^o$ and the constituent quark mass ratio $m_u/m_s\\sim 0.6$ which are all reasonable.
Fang, L; Huang, Y B; Yan, M L; Fang, Liu; Jin, Li; Huang, Yi-Bin; Yan, Mu-Lin
Searches for new quarks and leptons in Z boson decays
Searches for the decay of Z bosons into pairs of new quarks and leptons in a data sample including 455 hadronic Z decays are presented. The Z bosons were produced in electon-positron annihilations at the SLAC Linear Collider operating in the center-of-mass energy range from 89.2 to 93.0 GeV. The Standard Model provides no prediction for fermion masses and does not exclude new generations of fermions. The existence and masses of these new particles may provide valuable information to help understand the pattern of fermion masses, and physics beyond the Standard Model. Specific searches for top quarks and sequential fourth generation charge--1/3(b{prime}) quarks are made considering a variety of possible standard and non-standard decay modes. In addition, searches for sequential fourth generation massive neutrinos {nu}{sub 4} and their charged lepton partners L{sup {minus}} are pursued. The {nu}{sub 4} may be stable or decay through mixing to the lighter generations. The data sample is examined for new particle topologies of events with high-momentum isolated tracks, high-energy isolated photons, spherical event shapes, and detached vertices. No evidence is observed for the production of new quarks and leptons. 95% confidence lower mass limits of 40.7 GeV/c{sup 2} for the top quark and 42.0 GeV/c{sup 2} for the b{prime}-quark mass are obtained regardless of the branching fractions to the considered decay modes. A significant range of mixing matrix elements of {nu}{sub 4} to other generation neutrinos for a {nu}{sub 4} mass from 1 GeV/c{sup 2} to 43 GeV/c{sup 2} is excluded at 95% confidence level. Measurements of the upper limit of the invisible width of the Z exclude additional values of the {nu}{sub 4} mass and mixing matrix elements, and also permit the exclusion of a region in the L{sup {minus}} mass versus {nu}{sub 4} mass plane.
Van Kooten, R.J.
Flavor SU(3) analysis of charmless $B$ meson decays to two pseudoscalar mesons
Global fits to charmless B --> PP decays in the framework of flavor SU(3) symmetry are updated and improved without reference to the \\sin2\\beta measured from the charmonium decay modes. Fit results directly constrain the (\\bar\\rho,\\bar\\eta) vertex of the unitarity triangle, and are used to predict the branching ratios and CP asymmetries of all decay modes, including those of the B_s system. Different schemes of SU(3) breaking in decay amplitude sizes are analyzed. The major breaking effect between strangeness-conserving and strangeness-changing decays can be accounted for by including a ratio of decay constants in tree and color-suppressed amplitudes. The possibility of having a new physics contribution to K \\pi decays is also examined from the data fitting point of view.
Chiang, C W; Chiang, Cheng-Wei; Zhou, Yu-Feng
Measurement of the Moments of the Hadronic Invariant Mass Distribution in Semileptonic Beta Decays
Using 180 pb{sup -1} of data collected with the CDF II detector at the Tevatron, we measure the first two moments of the hadronic invariant mass-squared distribution in charmed semileptonic B decays. From these we determine the non-perturbative Heavy Quark Effective Theory parameters {Lambda} and {lambda}{sub 1} used to relate the B meson semileptonic branching ratio to the CKM matrix element |V{sub cb}|.
Acosta, D.; The CDF Collaboration TITLE=Measuremen
Search for Lepton Flavour Violating Decays Tau -> l Ks with the BABAR Detector
We present the search for the lepton flavour violating decay {tau} {yields} lK{sup 0}{sub s} with the BaBar experiment data. This process and many other lepton flavour violating {tau} decays, like {tau} {yields} {mu}{gamma} and {tau} {yields} lll, are one of the most promising channel to search for evidence of new physics. According to the Standard Model and the neutrino mixing parameters, branching fractions are estimated well below 10{sup -14}, but many models of new physics allow for branching fractions values close to the present experimental sensitivity. This analysis is based on a data sample of 469fb{sup -1} collected by BABAR detector at the PEP-II storage ring from 1999 to 2007, equivalent to 431 millions of {tau} pairs. the BABAR experiment, initially designed for studying CP violation in B mesons, has demonstrated to be one of the most suitable environments for studying {tau} decays. The tracking system, the calorimeter and the particle identification of BABAR, together with the knowledge of the {tau} initial energy, allow an extremely powerful rejection of background events that, for this analysis, is better than 10{sup -9}. Being {tau} {yields} lK{sup 0}{sub s} a decay mode without neutrinos, the signal {tau} decay can be fully reconstructed. Kinematical constraints are used in a fit that provides a decay tree reconstruction with a high resolution. For this analysis MC simulated events play a decisive role for estimating the signal efficiency and study the residual background. High statistics MC sample are produced simulating detector conditions for different periods of data collection, in order to reduce any discrepancies with the data. When discrepancies can not be removed, we perform studies to compute a correction factor or an estimation of systematic errors that need to be included in the final measurement. A significant improvement of the current result can be reached only with a higher statistics and, therefore, with a new collider providing a luminosity from 10 to 100 times more than PEP-II. A new detector, with improved performance and able to collect data in a high background environment, is also requested to fully exploit the capability of such amount of data. In fact, only keeping the efficiency and the background as similar as possible to present ones, we will be able to scale almost linearly the estimated upper limit according to the luminosity. The strong potential of improvement for the search of lepton flavour violation {tau} decays makes the building of such a machine highly desirable.
Cenci, Riccardo; /SLAC
Plutonium-238 alpha-decay damage study of the ceramic waste form.
An accelerated alpha-decay damage study of a glass-bonded sodalite ceramic waste form has recently been completed. The purpose of this study was to investigate the physical and chemical durability of the waste form after significant exposure to alpha decay. This accelerated alpha-decay study was performed by doping the ceramic waste form with {sup 238}Pu which has a much greater specific activity than {sup 239}Pu that is normally present in the waste form. The alpha-decay dose at the end of the four year study was approximately 1 x 10{sup 18} alpha-decays/gram of material. An equivalent time period for a similar dose of {sup 239}Pu would require approximately 1100 years. After four years of exposure to {sup 238}Pu alpha decay, the investigation observed little change to the physical or chemical durability of the ceramic waste form (CWF). Specifically, the {sup 238}Pu-loaded CWF maintained it's physical integrity, namely that the density remained constant and no cracking or phase de-bonding was observed. The materials chemical durability and phase stability also did not change significantly over the duration of the study. The only significant measured change was an increase of the unit-cell lattice parameters of the plutonium oxide and sodalite phases of the material and an increase in the release of salt components and plutonium of the waste form during leaching tests, but, as mentioned, these did not lead to any overall loss of waste form durability. The principal findings from this study are: (1) {sup 238}Pu-loaded CWF is similar in microstructure and phase composition to referenced waste form. (2) Pu was observed primarily as oxide comprised of aggregates of nano crystals with aggregates ranging in size from submicron to twenty microns in diameter. (3) Pu phases were primarily found in the intergranular glassy regions. (4) PuO phase shows expected unit cell volume expansion due to alpha decay damage of approximately 0.7%, and the sodalite phase unit cell volume has expanded slightly by 0.3% again, presumably due to alpha-decay damage. (5) No bulk sample swelling was observed. (6) No amorphization of sodalite or actinide bearing phases was observed after four years of alpha-decay damage. (7) No microcracks or phase de-bonding were observed in waste form samples aged for four years. (8) In some areas of the {sup 238}Pu doped ceramic waste form material bubbles and voids were found. Bubbles and voids with similar size and density were also found in ceramic waste form samples without actinide. These bubbles and voids are interpreted as pre-existing defects. However, some contribution to these bubbles and voids from helium gas can not be ruled out. (9) Chemical durability of {sup 238}Pu CWF has not changed significantly after four years of alpha-decay exposure except for an increase in the release of salt components and Pu. Still, the plutonium release from CWF is very low at less than 0.005 g/m{sup 2}.
Frank, S. M.; Barber, T. L.; Cummings, D. G.; DiSanto, T.; Esh, D.W.; Giglio, J. J.; Goff, K. M.; Johnson, S. G.; Kennedy, J. R.; Jue, J-F; Noy,M.; O'Holleran, T. P.; Sinkler, W.
Measurement of baryon production in B -meson decay
Using the CLEO detector at the Cornell Electron Storage Ring, we observe {ital B}-meson decays to {Lambda}{sub {ital c}}{sup +} and report on improved measurements of inclusive branching fractions and momentum spectra of other baryons. For the inclusive decay {ital {bar B}}{r arrow}{Lambda}{sub {ital c}}{sup +}{ital X} with {Lambda}{sub {ital c}}{sup +}{r arrow}{ital pK}{sup {minus}}{pi}{sup +}, we find that the product branching fraction {ital B}({ital {bar B}}{r arrow}{Lambda}{sub {ital c}}{sup +}{ital X}){ital B}({Lambda}{sub {ital c}}{sup +}{r arrow}{ital pK}{sup {minus}}{pi}{sup +})=(0.273{plus minus}0.051{plus minus} 0.039)%. Our measured inclusive branching fractions to noncharmed baryons are {ital B}({ital B}{r arrow}{ital pX})=(8.0{plus minus}0.5{plus minus}0.3)%, {ital B}({ital B}{r arrow}{Lambda}{ital X})=(3.8{plus minus}0.4{plus minus}0.6)%, and {ital B}({ital B}{r arrow}{Xi}{sup {minus}}{ital X})=(0.27{plus minus}0.05{plus minus}0.04)%. From these rates and studies of baryon-lepton and baryon-antibaryon correlations in {ital B} decays, we have estimated the branching fraction {ital B}({ital {bar B}}{r arrow}{Lambda}{sub {ital c}}{sup +}{ital X}) to be (6.4{plus minus}0.8{plus minus}0.8)%. Combining these results, we calculate {ital B}({Lambda}{sub {ital c}}{sup +}{r arrow}{ital pK}{sup {minus}}{pi}{sup +}) to be (4.3{plus minus}1.0{plus minus}0.8)%.
Crawford, G.; Fulton, R.; Jensen, T.; Johnson, D.R.; Kagan, H.; Kass, R.; Malchow, R.; Morrow, F.; Whitmore, J.; Wilson, P.; Bortoletto, D.; Brown, D.; Dominick, J.; McIlwain, R.L.; Miller, D.H.; Modesitt, M.; Ng, C.R.; Schaffner, S.F.; Shibata, E.I.; Shipsey, I.P.J.; Battle, M.; Kroha, H.; Sparks, K.; Thorndike, E.H.; Wang, C.; Alam, M.S.; Kim, I.J.; Li, W.C.; Lou, X.C.; Nemati, B.; Romero, V.; Sun, C.R.; Wang, P.; Zoeller, M.M.; Goldberg, M.; Haupt, T.; Horwitz, N.; Jain, V.; Kennett, R.; Mestayer, M.D.; Moneti, G.C.; Rozen, Y.; Rubin, P.; Skwarnicki, T.; Stone, S.; Thusalidas, M.; Yao, W.; Zhu, G.; Barnes, A.V.; Bartelt, J.; Csorna, S.E.; Letson, T.; Alexander, J.; Artuso, M.; Bebek, C.; Berkelman, K.; Besson, D.; Browder, T.; Cassel, D.G.; Cheu, E.; Coffman, D.M.; Drell, P.S.; Ehrlich, R.; Galik, R.S.; Garcia-Sciveres, M.; Geiser, B.; Gittelman, B.; Gray, S.W.; Hartill, D.L.; Heltsley, B.K.; Honscheid, K.; Kandaswamy, J.; Katayama, N.; Kreinick, D.L.; Lewis, J.D.; Ludwig, G.S.; Mas
Bioprospecting metagenomics of decaying wood: mining for new glycoside hydrolases
To efficiently deconstruct recalcitrant plant biomass to fermentable sugars in industrial processes, biocatalysts of higher performance and lower cost are required. The genetic diversity found in the metagenomes of natural microbial biomass decay communities may harbor such enzymes. Our goal was to discover and characterize new glycoside hydrolases (GHases) from microbial biomass decay communities, especially those from unknown or never previously cultivated microorganisms. From the metagenome sequences of an anaerobic microbial community actively decaying poplar biomass, we identified approximately 4,000 GHase homologs. Based on homology to GHase families/activities of interest and the quality of the sequences, candidates were selected for full-length cloning and subsequent expression. As an alternative strategy, a metagenome expression library was constructed and screened for GHase activities. These combined efforts resulted in the cloning of four novel GHases that could be successfully expressed in Escherichia coli. Further characterization showed that two enzymes showed significant activity on p-nitrophenyl-{alpha}-L-arabinofuranoside, one enzyme had significant activity against p-nitrophenyl-{beta}-D-glucopyranoside, and one enzyme showed significant activity against p-nitrophenyl-{beta}-D-xylopyranoside. Enzymes were also tested in the presence of ionic liquids. Metagenomics provides a good resource for mining novel biomass degrading enzymes and for screening of cellulolytic enzyme activities. The four GHases that were cloned may have potential application for deconstruction of biomass pretreated with ionic liquids, as they remain active in the presence of up to 20% ionic liquid (except for 1-ethyl-3-methylimidazolium diethyl phosphate). Alternatively, ionic liquids might be used to immobilize or stabilize these enzymes for minimal solvent processing of biomass.
Li L. L.; van der Lelie D.; Taghavi, S.; McCorkle, S. M.; Zhang, Y.-B.; Blewitt, M. G.; Brunecky, R.; Adney, W. S.; Himmel, M. E.; Brumm, P.; Drinkwater, C.; Mead, D. A.; Tringe, S. G.
Atomic nuclei decay modes by spontaneous emission of heavy ions
The great majority of the known nuclides with Z>40, including the so-called stable nuclides, are metastable with respect to several modes of spontaneous superasymmetric splitting. A model extended from the fission theory of alpha decay allows one to estimate the lifetimes and the branching ratios relative to the alpha decay for these natural radioactivities. From a huge amount of systematic calculations it is concluded that the process should proceed with maximum intensity in the trans-lead nuclei, where the minimum lifetime is obtained from parent-emitted heavy ion combinations leading to a magic (/sup 208/Pb) or almost magic daughter nucleus. More than 140 nuclides with atomic number smaller than 25 are possible candidates to be emitted from heavy nuclei, with half-lives in the range of 10/sup 10/--10/sup 30/ s: /sup 5/He, /sup 8en-dash10/Be, /sup 11,12/B, /sup 12en-dash16/C, /sup 13en-dash17/N, /sup 15en-dash22/O, /sup 18en-dash23/F, /sup 20en-dash26/Ne, /sup 23en-dash28/Na, /sup 23en-dash30/Mg, /sup 27en-dash32/Al, /sup 28en-dash36/Si, /sup 31en-dash39/P, /sup 32en-dash42/S, /sup 35en-dash45/Cl, /sup 37en-dash47/Ar, /sup 40en-dash49/ K, . .Ca, /sup 44en-dash53/ Sc, /sup 46en-dash53/Ti, /sup 48en-dash54/V, and /sup 49en-dash55/ Cr. The shell structure and the pairing effects are clearly manifested in these new decay modes.
Poenaru, D.N.; Ivascu, M.; Sndulescu, A.; Greiner, W.
Superparticle Mass Window from Leptogenesis and Decaying Gravitino Dark Matter
Gravitino dark matter, together with thermal leptogenesis, implies an upper bound on the masses of superparticles. In the case of broken R-parity the constraints from primordial nucleosynthesis are naturally satisfied and decaying gravitinos lead to characteristic signatures in high energy cosmic rays. We analyse the implications for supergravity models with universal boundary conditions at the grand unification scale. Together with low-energy observables one obtains a window of superparticle masses, which will soon be probed at the LHC, and a range of allowed reheating temperatures.
Wilfried Buchmuller; Motoi Endo; Tetsuo Shindou
Measurement of $\\psi(2S)$ decays to baryon pairs
A sample of 3.95M $\\psi(2S)$ decays registered in the BES detector are used to study final states containing pairs of octet and decuplet baryons. We report branching fractions for $\\psi(2S)\\to p\\bar{p}$, $\\Lambda\\bar{\\Lambda}$, $\\Sigma^0\\bar{\\Sigma}{}^0$, $\\Xi^-\\bar{\\Xi}{}^+$, $\\Delta^{++}\\bar{\\Delta}{}^{--}$, $\\Sigma^+(1385)\\bar{\\Sigma}{}^-(1385 )$, $\\Xi^0(1530)\\bar{\\Xi}{}^0(1530)$, and $\\Omega^-\\bar{\\Omega}{}^+$. These results are compared to expectations based on the SU(3)-flavor symmetry, factorization, and perturbative QCD.
Bai, J Z; Bian, J G; Blum, I K; Chen, A D; Chen, G P; Chen, H F; Chen, H S; Chen, J; Chen Jia Chao; Chen, X D; Chen, Y; Chen, Y B; Cheng Bao Sen; Choi, J B; Cui, X Z; Ding, H L; Dong, L Y; Du, Z Z; Dunwoodie, W M; Gao, C S; Gao, M L; Gao, S Q; Gratton, P; Gu, J H; Gu, S D; Gu, W X; Guo, Y N; Guo, Z J; Han, S W; Han, Y; Harris, F A; He, J; He, J T; He, K L; He, M; Heng, Y K; Hitlin, D G; Hu, G Y; Hu, H M; Hu, J L; Hu, Q H; Hu, T; Huang, G S; Huang, X P; Huang, Y Z; Izen, J M; Jiang, C H; Jin, Y; Jones, B D; Ju, X; Kang, J S; Ke, Z J; Kelsey, M H; Kim, B K; Kim, H J; Kim, S K; Kim, T Y; Kong, D; Lai, Y F; Lang, P F; Lankford, A J; Li, C G; Li, D; Li, H B; Li, J; Li, J C; Li, P Q; Li, W; Li, W G; Li, X H; Li Xiao Nan; Li Xue Qian; Li Zhong Chao; Liu, B; Liu, F; Liu Feng; Liu, H M; Liu, J; Liu, J P; Liu, R G; Liu, Y; Liu, Z X; Lou, X C; Lowery, B; Lu, G R; Lu, F; Lu, J G; Luo, X L; Ma, E C; Ma, J M; Malchow, R L; Mao, H S; Mao, Z P; Meng, X C; Mo, X H; Nie, J; Olsen, S L; Oyang, J Y T; Paluselli, D; Pan, L J; Panetta, J; Park, H; Porter, F; Qi, N D; Qi, X R; Qian, C D; Qiu, J F; Qu, Y H; Que, Y K; Rong, G; Schernau, M; Shao, Y Y; Shen, B W; Shen, D L; Shen, H; Shen, H Y; Shen, X Y; Shi, F; Shi, H Z; Song, X F; Standifird, J; Suh, J Y; Sun, H S; Sun, L F; Sun, Y Z; Tang, S Q; Toki, W; Tong, G L; Varner, G S; Wang, F; Wang, L; Wang, L S; Wang, L Z; Wang, P; Wang, P L; Wang, S M; Wang, Y Y; Wang, Z Y; Weaver, M; Wei, C L; Wu, N; Wu, Y G; Xi, D M; Xia, X M; Xie, Y; Xie, Y H; Xu, G F; Xue, S T; Yan, J; Yan, W G; Yang, C M; Yang, C Y; Yang, H X; Yang, W; Yang, X F; Ye, M H; Ye Shu Wei; Ye, Y X; Yu, C S; Yu, C X; Yu, G W; Yu Yu Hei; Yu, Z Q; Yuan, C Z; Yuan, Y; Zhang Bing Yun; Zhang, C; Zhang, C C; Zhang, D H; De Hong Zhang; Zhang, H L; Zhang, J; Zhang, J W; Zhang, L; Zhang Lei; Zhang, L S; Zhang, P; Zhang, Q J; Zhang, S Q; Zhang, X Y; Zhang, Y Y; Zhao, D X; Zhao, H W; Jia Wei Zhao; Zhao Jia Wei; Zhao, M; Zhao Wei Ren; Zhao, Z G; Zheng Jian Ping; Zheng Lin Sheng; Zheng Zhi Peng; Zhou, B Q; Zhou, L; Zhu, K J; Zhu, Q M; Zhu, Y C; Zhu, Y S; Zhu, Z A; Zhuang, B A
Distinguishing Spins in Decay Chains at the Large Hadron Collider.
ar X iv :h ep -p h/ 06 05 28 6v 4 2 9 A ug 2 00 8 Preprint typeset in JHEP style - PAPER VERSION Cavendish�HEP�06/11(rev.) Distinguishing Spins in Decay Chains at the Large Hadron Collider? Christiana Athanasiou1, Christopher G. Lester2... particles at the LHC,� Phys. Lett. B596 (2004) 205�212, hep-ph/0405052. [2] T. Goto, K. Kawagoe, and M. M. Nojiri, �Study of the slepton non-universality at the CERN Large Hadron Collider,� Phys. Rev. D70 (2004) 075016, hep-ph/0406317. � 21 � [3] H. C. Cheng...
Athanasiou, Christiana; Lester, Christopher G; Smillie, Jennifer M; Webber, Bryan R
Distinguishing Spins in Decay Chains at the Large Hadron Collider
Two Photon Decays of Charmonia from Lattice QCD
We make the first calculation in lattice QCD of two-photon decays of mesons. Working in the charmonium sector, using the LSZ reduction to relate a photon to a sum of hadronic vector eigenstates, we compute form-factors in both the space-like and time-like domains for the transitions $\\eta_c \\to \\gamma^* \\gamma^*$ and $\\chi_{c0} \\to \\gamma^* \\gamma^*$. At the on-shell point we find approximate agreement with experimental world-average values.
Jozef J. Dudek; Robert G. Edwards
Indoor radon and decay products: Concentrations, causes, and control strategies
This report is another in the on going technical report series that addresses various aspects of the DOE Radon Research Program. It provides an overview of what is known about the behavior of radon and its decay products in the indoor environment and examines the manner in which several important classes of factors -- structural, geological, and meteorological -- affect indoor radon concentrations. Information on US indoor radon concentrations, currently available monitoring methods and novel radon control strategies are also explored. 238 refs., 22 figs., 9 tabs.
Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.
Cosmological Bounds on an Invisibly Decaying Higgs Boson
We derive bounds on the Higgs boson coupling $g^{\\prime}$ to a stable light scalar which is regarded as a collisional dark matter candidate. We study the behaviour of this scalar, that we refer to as phion ($\\phi$), in the early Universe for different ranges of its mass. We find that a phion in the mass range of $100 \\mev$ is excluded, while if its mass is about $1 \\gev$, a rather large coupling constant, $g^{\\prime} \\gsim 2$, and $m_h \\lsim 130 \\gev$ are required in order to avoid overabundance. In the latter case, the invisible decay mode of the Higgs boson is dominant.
O. Bertolami; M. C. Bento; R. Rosenfeld
Precision Measurement of the Neutron Beta-Decay Asymmetry
A new measurement of the neutron $\\beta$-decay asymmetry $A_0$ has been carried out by the UCNA collaboration using polarized ultracold neutrons (UCN) from the solid deuterium UCN source at the Los Alamos Neutron Science Center (LANSCE). Improvements in the experiment have led to reductions in both statistical and systematic uncertainties leading to $A_0 = -0.11954(55)_{\\rm stat.}(98)_{\\rm syst.}$, corresponding to the ratio of axial-vector to vector coupling $\\lambda \\equiv g_A/g_V = -1.2756(30)$.
Mendenhall, M P; Bagdasarova, Y; Berguno, D B; Broussard, L J; Carr, R; Clayton, S; Currie, S; Ding, X; Garc�a, A; Geltenbort, P; Hickerson, K P; Hoagland, J; Hogan, G E; Holley, A T; Hong, R; Ito, T M; Filippone, B W; Knecht, A; Liu, C -Y; Liu, J L; Makela, M; Mammei, R R; Martin, J W; Melconian, D; Moore, S D; Morris, C L; Galv�n, A P�rez; Picker, R; Pitt, M L; Plaster, B; Rios, R; Saunders, A; Seestrom, S J; Sondheim, W E; Tatar, E; Vogelaar, R B; VornDick, B; Wrede, C; Young, A R; Zeck, B A
M. P. Mendenhall; R. W. Pattie Jr; Y. Bagdasarova; D. B. Berguno; L. J. Broussard; R. Carr; S. Currie; X. Ding; B. W. Filippone; A. Garc�a; P. Geltenbort; K. P. Hickerson; J. Hoagland; A. T. Holley; R. Hong; T. M. Ito; A. Knecht; C. -Y. Liu; J. L. Liu; M. Makela; R. R. Mammei; J. W. Martin; D. Melconian; S. D. Moore; C. L. Morris; A. P�rez Galv�n; R. Picker; M. L. Pitt; B. Plaster; J. C. Ramsey; R. Rios; A. Saunders; S. J. Seestrom; E. I. Sharapov; W. E. Sondheim; E. Tatar; R. B. Vogelaar; B. VornDick; C. Wrede; A. R. Young; B. A. Zeck
Efficient double beta decay nuclear matrix elements computations
We have developed a shell model code for the accurate computation of the two-body matrix elements of the transition operators involved in the neutrinoless double beta decay. This code features coupled cluster method short-range correlations with Jastrow-like functions, finite nucleon size effect and higher order nucleon current corrections. We present the results obtained for {sup 48}Ca and {sup 82}Se, then we compare them with other results in the literature. In the case of {sup 48}Ca, we also study the contributions of the included effects and find good agreement with other published results.
Neacsu, Andrei [Horia Hulubei Foundation (FHH) 407 Atomistilor, Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH) 30 Reactorului, Magurele-Bucharest 077125 (Romania)
Search for the Rare Leptonic Decays B^+ \\to l^+ \
We have performed a search for the rare leptonic decays B{sup +} {yields} {ell}{sup +} {nu}{sub {ell}}({ell} = e,{mu}), using data collected at the ?(4S) resonance by the BABAR detector at the PEP-II storage ring. In a sample of 468 x 10{sup 6} B{bar B} pairs we find no evidence for a signal and set an upper limit on the branching fractions B(B{sup +} {yields} e{sup +}{nu}{sub e}) < 1.9 x 10{sup -6} at the 90% confidence level, using a Bayesian approach.
Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /INFN, Naples /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /SLAC /South Carolina U. /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison
Determination of the b_s lifetime using hadronic decays
The authors present a measurement of the B{sub s}{sup 0} meson lifetime using fully and partially reconstructed hadronic decays B{sub s}{sup 0} {yields} D{sub s}{sup -} {pi}{sup +}(X) followed by D{sub s}{sup -} {yields} {phi}{pi}{sup -}. The data sample was recorded with the CDF II detector at the Fermilab Tevatron and corresponds to an integrated luminosity of 1.3 fb{sup -1} from p{bar p} collisions at {radical}s = 1.96 TeV.
Deisher, A.J.; /LBL, Berkeley
Role of the isovector nucleon-nucleus interaction potential in nonmesonic hypernuclear decay
We develop a theoretical finite nucleus framework for the evaluation of the coincidence number of pairs N{sub nN} and the asymmetry parameter a{sub {Lambda}} in nonmesonic hypernuclear decay {Lambda}N{yields}nN, and introduce the effect of final-state interactions. The primary nonmesonic weak hyperon-nucleon decay process is described through the independent-particle shell model. We work within the 2p1h subspace of final states, assuming a simple approach for finite nuclei based on the eikonal approximation. An optical potential including the nucleon-nucleus isoscalar and isovector interactions is introduced to take into account the minimum nuclear-medium effects. The calculated values for {sub {Lambda}}{sup 5}He and {sub {Lambda}}{sup 12}C show that our treatment of final-state interactions, even those considered as restricted to a subspace of states, brings the independent-particle model results closer to the experimental data.
Barbero, C.; Mariano, A. [Facultad de Ciencias Exactas, Departamento de Fisica, Universidad Nacional de La Plata, 1900 La Plata (Argentina); Instituto de Fisica La Plata, CONICET, 1900 La Plata (Argentina); Duarte, S. B. [Centro Brasileiro de Pesquisas Fisicas, Rua Dr Xavier Sigaud 150 CEP 22290-180, Rio de Janeiro-RJ (Brazil)
Search for Higgs decays to tau lepton pairs at the Tevatron
We present a search for neutral supersymmetric Higgs bosons decaying to tau+tau- pairs produced in ppbar collisions at sqrt{s}=1.96 TeV. The data have been collected with the CDF II and D0 detectors at the Tevatron collider at Fermilab (1 fb^-1 of integrated luminosity per experiment). No significant excess above the standard model backgrounds is observed. We set exclusion limits on the Higgs production cross-section times the branching fraction of its decay to tau+tau- pairs for Higgs masses in the range from 90 to 250 GeV/c^2. We also set exclusion limits on MSSM parameters m_A and tan_beta in several benchmark scenarios.
I. Kravchenko; for the CDF; D0 Collaborations
Six-Quark Decays of the Higgs Boson in Supersymmetry with R-Parity Violation
Both electroweak precision measurements and simple supersymmetric extensions of the standard model prefer a mass of the Higgs boson less than the experimental lower limit (on a standard-model-like Higgs boson) of 114 GeV. We show that supersymmetric models with R parity violation and baryon-number violation have a significant range of parameter space in which the Higgs boson dominantly decays to six jets. These decays are much more weakly constrained by current CERN LEP analyses and would allow for a Higgs boson mass near that of the Z. In general, lighter scalar quark and other superpartner masses are allowed. The Higgs boson would potentially be discovered at hadron colliders via the appearance of new displaced vertices.
Carpenter, Linda M.; Kaplan, David E.; Rhee, Eun-Jung [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, Maryland 21218 (United States)
Search for CP Violation in the Decay D+/- to Ks pi+/-
We report on a search for CP violation in the decay D{sup {+-}} {yields} K{sub S}{sup 0}{pi}{sup {+-}} using a data set corresponding to an integrated luminosity of 469 fb{sup -1} collected with the BABAR detector at the PEP-II asymmetric energy e{sup +}e{sup -} storage rings. The CP-violating decay rate asymmetry A{sub CP} is determined to be (-0.44 {+-} 0.13(stat) {+-} 0.10(syst))%, consistent with zero at 2.7 {sigma} and with the standard model prediction of (-0.332 {+-} 0.006)%. This is currently the most precise measurement of this parameter.
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /INFN, Bari; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
Challenges for a reliable shell model description of the neutrinoless double beta decay matrix elements
Assuming that the neutrinos are Majorana particles and the neutrinoless double beta (0{nu}{beta}{beta}) decay is observed, a reliable 0{nu}{beta}{beta} matrix element is necessary to decide the neutrino mass hierarchy and the minimum neutrino mass. Many nuclear structure techniques, including the shell model, are presently used to calculate these matrix elements. In the last few years one could see a slow convergence of these results, but not yet at a level of 20 several shell model effective interactions and varying other parameters, finding results in a range that spans about 20In this contribution we describe challenges for obtaining reliable shell model 0{nu}{beta}{beta} matrix elements, with emphasis to {sup 76}Ge and {sup 82}Se decays.
Search for the neutral MSSM Higgs bosons in the ditau decay channels at CDF Run II
This thesis presents the results on a search for the neutral MSSM Higgs bosons decaying to tau pairs, with least one of these taus decays leptonically. The search was performed with a sample of 1.8 fb{sup -1} of proton-antiproton collisions at {radical}s = 1.96 TeV provided by the Tevatron and collected by CDF Run II. No significant excess over the Standard Model prediction was found and a 95% confidence level exclusion limit have been set on the cross section times branching ratio as a function of the Higgs boson mass. This limit has been translated into the MSSM Higgs sector parameter plane, tan{beta} vs. M{sub A}, for the four different benchmark scenarios.
Cuenca Almenar, Cristobal; /Valencia U., IFIC
Search for B ? Kll and B ? K*ll decays
We have searched for the flavor-changing-neutral-current (FCNC) decays B ! K` + ` \\Gamma and B ! K ` + ` \\Gamma . Using a data sample of 2.17\\Theta10 6 B B events, we find 90% confidence level upper limits on the branching ratios: BR(B \\Gamma ! K \\Gamma e + e \\Gamma ) ! 1:2 \\Theta 10 \\Gamma5 , BR( B 0 ! K 0 e + e \\Gamma ) ! 1:6 \\Theta 10 \\Gamma5 , BR(B \\Gamma ! K \\Gamma + \\Gamma ) ! 0:9 \\Theta 10 \\Gamma5 , BR( B 0 ! K 0 + \\Gamma ) ! 3:1 \\Theta 10 \\Gamma5 , BR(B \\Gamma ! K \\Gamma e \\Sigma \\Upsilon ) ! 1:2 \\Theta 10 \\Gamma5 , and BR( B 0 ! K 0 e \\Sigma \\Upsilon ) ! 2:7 \\Theta 10 \\Gamma5 . The limit on B 0 ! K 0 e + e \\Gamma is within a factor of 3 of the branching ratio predicted by the Standard Model. Permanent address: University of Hawaii at Manoa y Permanent address: INP, Novosibirsk, Russia 2 In the Standard Model (SM), flavor-changing-neutral-current (FCNC) decays are fo...
R. Balest
Measurement of Cabibbo suppressed decays of the $\\tau$ lepton
Branching ratios for the dominant Cabibbo-suppressed decays of the \\tau lepton have been measured by CLEO~II in e^+ e^- annihilation at CESR (\\sqrt{s} \\sim 10.6~GeV) using kaons with momenta below 0.7\\ \\rm GeV/c. The inclusive branching ratio into one charged kaon is (1.60 \\pm 0.12 \\pm 0.19)\\%. For the exclusive decays, B(\\tau \\to K^-) = (0.66 \\pm 0.07 \\pm 0.09)\\%, B(\\tau \\to K^- \\pi^0) = (0.51 \\pm 0.10 \\pm 0.07)\\%, and, based on three events, B(\\tau \\to K^- \\pi^0 \\pi^0) < 0.3\\% at the 90\\% confidence level. These represent significant improvements over previous results. B(\\tau\\to K^- \\pi^0) is measured for the first time with exclusive \\pi^0 reconstruction. hardcopies with figures can be obtained by writing to: Pam Morehouse preprint secretary Newman Lab Cornell University Ithaca, NY 14853 or by sending mail to: email@example.com
Battle, M; Kwon, Y; Roberts, S; Thorndike, E H; Wang, C H; Dominick, J; Lambrecht, M; Sanghera, S; Shelkov, V; Skwarnicki, T; Stroynowski, R; Volobuev, I P; Wei, G; Zadorozhny, P; Artuso, M; Goldberg, M; He, D; Horwitz, N; Kennett, R; Mountain, R; Moneti, G C; Muheim, F; Mukhin, Y; Playfer, S; Rozen, Y; Stone, S; Thulasidas, M; Vasseur, G; Zhu, G; Bartelt, J; Csorna, S E; Egyed, Z; Jain, V; Kinoshita, K; Edwards, K W; Ogg, M; Britton, D I; Hyatt, E R F; MacFarlane, D B; Patel, P M; Akerib, D S; Barish, B C; Chadha, M; Chan, S; Cowen, D F; Eigen, G; Miller, J S; O'Grady, C; Urheim, J; Weinstein, A J; Acosta, D; Athanas, M; Masek, G E; Paar, H P; Sivertz, M; Gronberg, J B; Kutschke, R; Menary, S R; Morrison, R J; Nakanishi, S; Nelson, H N; Nelson, T K; Qiao, C; Richman, J D; Ryd, A; Tajima, H; Sperka, D; Witherell, M S; Procario, M; Balest, R; Cho, K; Daoudi, M; Ford, W T; Johnson, D R; Lingel, K; Lohner, M; Rankin, P; Smith, J G; Alexander, J P; Bebek, C; Berkelman, K; Bloom, K; Browder, T E; Cassel, David G; Cho, H A; Coffman, D M; Drell, P S; Ehrlich, R; Gaidarev, P B; Galik, R S; Garc�a-Sciveres, M; Geiser, B; Gittelman, B; Gray, S W; Hartill, D L; Heltsley, B K; Jones, C D; Jones, S L; Kandaswamy, J; Katayama, N; Kim, P C; Kreinick, D L; Ludwig, G S; Masui, J; Mevissen, J; Mistry, N B; Ng, C R; Nordberg, E; Patterson, J R; Peterson, D; Riley, D; Salman, S; Sapper, M; W�rthwein, F; Avery, P; Freyberger, A P; Rodr�guez, J; Stephens, R; Yang, S; Yelton, J; Cinabro, D; Henderson, S; Liu, T; Saulnier, M; Wilson, R; Yamamoto, H; Bergfeld, T; Eisenstein, B I; Gollin, G; Ong, B; Palmer, M; Selen, M; Thaler, J J; Sadoff, A J; Ammar, R; Ball, S; Baringer, P; Bean, A; Besson, D; Coppage, D; Copty, N K; Davis, R; Hancock, N; Kelly, M; Kwak, N; Lam, H; Kubota, Y; Lattery, M; Nelson, J K; Patton, S; Perticone, D; Poling, R A; Savinov, V; Schrenk, S; Wang, R; Alam, M S; Kim, I J; Nemati, B; O'Neill, J J; Severini, H; Sun, C R; Zoeller, M M; Crawford, G; Daubenmier, C M; Fulton, R; Fujino, D; Gan, K K; Honscheid, K; Kagan, H; Kass, R; Lee, J; Malchow, R L; Skovpen, Y; Sung, M; White, C; Butler, F; Fu, X; Kalbfleisch, G R; Ross, W R; Skubic, P L; Snow, J; Wang, P L; Wood, M; Brown, D N; Fast, J; McIlwain, R L; Miao, T; Miller, D H; Modesitt, M; Payne, D; Shibata, E I; Shipsey, I P J; Wang Pei Ning
Study light scalar meson property from heavy meson decays
In the SU(3) symmetry limit, the ratio R {identical_to} (B(D{sup +{yields}}f{sub 0}l{sup +{nu}})+B(D{sup +{yields}{sigma}}l{sup +{nu}})/B(D{sup +{yields}}a{sub 0}{sup 0}l{sup +{nu}})) is equal to 1 if the scalar mesons are q-barq states, while it is 3 if these mesons are tentraquark states. This ratio provides a model-independent way to distinguish the descriptions for light scalar mesons. It also applies to the B{sup -{yields}}Sl{sup -{nu}}-bar, and B{sup 0}-bar{yields}J/{psi}({eta}{sub c})S decays. The SU(3) symmetry breaking effect is found to be under control, which will not spoil our method. The branching fractions of the D{sup +{yields}}Sl{sup +{nu}}, B{sup -{yields}}Sl{sup -{nu}}-bar and B{sup 0}-bar{yields}J/{psi}({eta}{sub c})S decays roughly have the order 10{sup -4}, 10{sup -5} and 10{sup -6}, respectively. The B factory experiments and ongoing BEPC-II experiments are able to measure these channels and accordingly to provide the detailed information of the scalar meson inner structure.
Lu Caidian [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Wang Wei [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Bari 70126 (Italy)
Recent Results in Semileptonic B Decays with BaBar
In this note, recent results of studies of semileptonic B meson decays from BABAR are discussed and preliminary results given. In particular, a recent measurement of {Beta}(B {yields} D{sup (*)}{tau}{nu}) and the ratio {Beta}(B {yields} D{sup (*)}{tau}{nu})/{Beta}(B {yields} D{sup (*)}{ell}{nu}) is presented. For the D* mode, a branching fraction of 1.79 {+-} 0.13(stat) {+-} 0.17(syst) is found, with a ratio of 0.325 {+-} 0.023(stat) {+-} 0.027(syst). For the D mode, the results are 1.04 {+-} 0.12(stat) {+-} 0.14(syst) and 0.456 {+-} 0.053(stat) {+-} 0.056(syst), respectively. In addition, a study of B{sub s} production and semileptonic decays using data collected in a center-of-mass energy region above the {Upsilon}(4S) resonance is discussed. The semileptonic branching fraction {Beta}(B{sub s} {yields} {ell}{nu}X) is measured to be 9.9{sub -2.1}{sup +2.6}(stat){sub -2.0}{sup +1.3}(syst).
Hamilton, B.K.; /Maryland U.
Gas-Cooled Fast Reactor (GFR) Decay Heat Removal Concepts
Current research and development on the Gas-Cooled Fast Reactor (GFR) has focused on the design of safety systems that will remove the decay heat during accident conditions, ion irradiations of candidate ceramic materials, joining studies of oxide dispersion strengthened alloys; and within the Advanced Fuel Cycle Initiative (AFCI) the fabrication of carbide fuels and ceramic fuel matrix materials, development of non-halide precursor low density and high density ceramic coatings, and neutron irradiation of candidate ceramic fuel matrix and metallic materials. The vast majority of this work has focused on the reference design for the GFR: a helium-cooled, direct power conversion system that will operate with an outlet temperature of 850�C at 7 MPa. In addition to the work being performed in the United States, seven international partners under the Generation IV International Forum (GIF) have identified their interest in participating in research related to the development of the GFR. These are Euratom (European Commission), France, Japan, South Africa, South Korea, Switzerland, and the United Kingdom. Of these, Euratom (including the United Kingdom), France, and Japan have active research activities with respect to the GFR. The research includes GFR design and safety, and fuels/in-core materials/fuel cycle projects. This report is a compilation of work performed on decay heat removal systems for a 2400 MWt GFR during this fiscal year (FY05).
K. D. Weaver; L-Y. Cheng; H. Ludewig; J. Jo
Triggers for displaced decays of long-lived neutral particles in the ATLAS detector
A set of three dedicated triggers designed to detect long-lived neutral particles decaying throughout the ATLAS detector to a pair of hadronic jets is described. The efficiencies of the triggers for selecting displaced decays as a function of the decay position are presented for simulated events. The effect of pile-up interactions on the trigger efficiencies and the dependence of the trigger rate on instantaneous luminosity during the 2012 data-taking period at the LHC are discussed.
ATLAS Collaboration
Rare B{sub s} decays to {eta} and {eta}' final states
We study exclusive B{sub s} decays to final states with {eta} and {eta}{sup '}, induced by the rare b{yields}sl{sup +}l{sup -} and b{yields}s{nu}{nu} transitions. Differential decay rates and total branching fractions are predicted in the standard model, adopting the flavor scheme for the description of the {eta}-{eta}{sup '} mixing. We discuss the theoretical uncertainty related to the hadronic matrix elements. We also consider these decay modes in a new physics scenario with a single universal extra dimension, studying the dependence of branching ratios and decay distributions on the compactification scale R{sup -1} of the extra dimension.
Carlucci, M. V. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari (Italy); Dipartimento di Fisica, Universita di Bari (Italy); Colangelo, P.; De Fazio, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari (Italy)
Exclusive decay of $?$ into $J/?+?_{c0,1,2}$
We study the $\\Upsilon$ exclusive decay into double charmonium, specifically, the $S$-wave charmonium $ J/\\psi$ plus the $P$-wave charmonium $\\chi_{c0,1,2}$ in the NRQCD factorization framework. Three distinct decay mechanisms, i.e., the strong, electromagnetic and radiative decay channels are included and their interference effects are investigated. The decay processes $\\Upsilon(1S,2S,3S)\\to J/\\psi+\\chi_{c1,0}$ are predicted to have the branching fractions of order $10^{-6}$, which should be observed in the prospective Super $B$ factory.
Jia Xu; Hai-Rong Dong; Feng Feng; Ying-Jia Gao; Yu Jia
Exclusive decay of $\\Upsilon$ into $J/\\psi+\\chi_{c0,1,2}$
Xu, Jia; Feng, Feng; Gao, Ying-Jia; Jia, Yu
Universality of Decay out of Superdeformed Bands in the 190 Mass Region
Superdeformed nuclei in the 190 mass region exhibit a striking universality in their decay-out profiles. We show that this universality can be explained in the two-level model of superdeformed decay as related to a strong separation of energy scales: a higher scale related to the nuclear interactions, and a lower scale caused by electromagnetic decay. Furthermore, we present the results of the two-level model for all decays for which sufficient data are known, including statistical extraction of the matrix element for tunneling through the potential barrier.
D. M. Cardamone; B. R. Barrett; C. A. Stafford
Thermal decay in underfloor air distribution (UFAD) systems: Fundamentals and influence on system performance
Inc. , 2004. ASHRAE Fundamentals Handbook, Chapter 14,distribution (UFAD) systems: Fundamentals and influence onwas used to explain the fundamentals of thermal decay, to
Lee, Kwang Ho; Schiavon, Stefano; Bauman, Fred; Webster, Tom
Inverse beta decay reaction in $^{232}$Th and $^{233}$U fission antineutrino flux
Energy spectra of antineutrinos coming from $^{232}$Th and $^{233}$U neutron-induced fission are calculated, relevant inverse beta decay $\\bar{{\
G. Domogatski; V. Kopeikin; L. Mikaelyan; V. Sinev
MIGRATION BEHAVIOR OF THE 234U -> 230TH -> 226Ra -> DECAY CHAIN
Release of Decaying Radionuclides Through Sorbing Media,"the Migration of Radionuclides Through Geologic Media," UCB-for the Migration of Radionuclides Through Sorbing Media
Higashi, K.
Exclusive search for Higgs boson to gamma-gamma decay via vector boson fusion production mechanism.
??We perform an exclusive search for the Higgs boson to gamma-gamma decay via vector boson fusion. We utilize the characteristic features of vector boson fusion,� (more)
Rankin, Dylan Sheldon
Studies on Nuclear Reactors, Power Developed by Decay of Fissin Fragments
A study is made of the power developed by the decay of fission fragments arising during the operation of a U235 reactor.
Greenfield, M.A.
The {beta}-Decay Properties of Scissors Mode 1{sup +} States in {sup 164}Er
The beta decay properties of collective I{sup {pi}}K = 1{sup +}1 states in doubly even deformed {sup 164}Er nuclei are investigated in the framework of the rotational invariant random-phase approximation. It is shown that an essential decrease of the rate of the allowed {beta}-decay to the excited 1{sup +}-states as compared with that to the ground state may be due to the orbital nature of the states. The model Hamiltonian includes restoring rotational invariance of the deformed single particle Hamiltonian forces and the spin-spin interactions. The analytical expressions for the Gamov-Teller (G-T) and Fermi (F) decay matrix elements are derived. The single-particle energies were obtained from the Warsaw deformed Woods-Saxon potential with deformation parameter {delta}{sub 2} = 0.24. The numerical results for {beta}{sup +} transition from {sup 164}Tm to {sup 164}Er indicate the importance of using rotational invariant Hamiltonian to explain experimental data.
Yildirim, Z.; Kuliev, A.; Ozkan, S. [Sakarya University, Department of Physics, 54100, Sakarya (Turkey); Guliyev, E. [Institute of Physics, Academy of Sciences, H. Cavid Avenue 33, Baku (Azerbaijan); Institut fur Kernphysik, Technische Universitat Darmstadt, Darmstadt (Germany)
Gravitino Decays and the Cosmological Lithium Problem in Light of the LHC Higgs and Supersymmetry Searches
We studied previously the impact on light-element abundances of gravitinos decaying during or after Big-Bang nucleosynthesis (BBN). We found regions of the gravitino mass m_{3/2} and abundance zeta_{3/2} plane where its decays could reconcile the calculated abundance of Li7 with observation without perturbing the other light-element abundances unacceptably. Here we revisit this issue in light of LHC measurements of the Higgs mass and constraints on supersymmetric model parameters, as well as updates in the astrophysical measurements of light-element abundances. In addition to the constrained minimal supersymmetric extension of the Standard Model with universal soft supersymmetry-breaking masses at the GUT scale (the CMSSM) studied previously, we also study models with universality imposed below the GUT scale and models with non-universal Higgs masses (NUHM1). We calculate the total likelihood function for the light-element abundances, taking into account the observational uncertainties. We find that gravitino decays provide a robust solution to the cosmological Li7 problem along strips in the (m_{3/2}, zeta_{3/2}) plane along which the abundances of deuterium, He4 and Li7 may be fit with chi^2_min lithium abundance is taken from globular cluster data.
Richard H. Cyburt; John Ellis; Brian D. Fields; Feng Luo; Keith A. Olive; Vassilis C. Spanos
Angular correlations in top quark decays in standard model extensions
The CMS Collaboration at the CERN LHC has searched for the t-channel single top quark production using the spin correlation of the t-channel. The signal extraction and cross section measurement rely on the angular distribution of the charged lepton in the top quark decays, the angle between the charged lepton momentum and top spin in the top rest frame. The behavior of the angular distribution is a distinct slope for the t-channel single top (signal) while it is flat for the backgrounds. In this Brief Report, we investigate the contributions which this spin correlation may receive from a two-Higgs doublet model, a top-color assisted technicolor (TC2) and the noncommutative extension of the standard model.
Batebi, S. [Science and Research Branch, Islamic Azad University (IAU), Tehran (Iran, Islamic Republic of); Etesami, S. M. [School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of); Physics Department, Isfahan University of Technology (IUT), P.O. Box 11365-9161, Isfahan (Iran, Islamic Republic of); Mohammadi-Najafabadi, M. [Physics Department, Isfahan University of Technology (IUT), P.O. Box 11365-9161, Isfahan (Iran, Islamic Republic of)
Electron Capture Reactions and Beta Decays in Steller Environments
Electron capture reactions on Ni and Co isotopes are investigated by shell model calculations in steller environments. The capture rates depend sensitively on the distribution of the Gamow-Teller (GT) strength. The capture rates obtained by using GXPF1J Hamiltonian for fp-shell are found to be consistent with the rates obtained from experimental GT strength in {sup 58}Ni and {sup 60}Ni. Capture rates in Co isotopes, where there were large discrepancies among previous calculations, are also investigated. Beta decays of the N = 126 isotones are studied by shell model calculations taking into account both the GT and first-forbidden (FF) transitions. The FF transitions are found to be important to reduce the half-lives by twice to several times of those by the GT contributions only. Implications of the short half-lives of the waiting point nuclei on the r-process nucleosynthesis are discussed for various astrophysical conditions.
Suzuki, T. [Department of Physics and Graduate School of Integrated Basic Sciences, College of Humanities and Sciences, Nihon University, Sakurajosui 3-25-40, Setagaya-ku, Tokyo 156-8550, Japan and Center for Nuclear Study, University of Tokyo, Hirosawa, Wako-shi, Saitama, 351-0198 (Japan); Mao, H. [Graduate School of Integrated Basic Sciences, Nihon University, Sakurajosui-3-25-40, Setagaya-ku, Tokyo 156-8550, Japan and ENSPS, Pole API-Parc d'Innovation, Boulevard Sebastien Brant, BP 10413, 67412 ILLKIRCH CEDEXL (France); Honma, M. [Center for Mathematical Sciences, University of Aizu, Aizu-Wakamatsu, Fukushima 965-8580 (Japan); Yoshida, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kajino, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan) and National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Otsuka, T. [Department of Physics and Center for Nuclear Study, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan) and RIKEN, Hirosawa, Wako-shi, Saitama 351-0198 (Japan)
Search for B+ meson decay to a1+ K*0
We present a search for the decay B{sup +} --> {alpha}{sup +}{sub 1}(1260)K*{sup 0}(892). The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, represent 465 million B{anti B} pairs produced in e{sup +}e{sup -} annihilation at the energy of the {Upsilon}(4S). We find no significant signal and set an upper limit at 90% confidence level on the product of branching fractions B(B{sup +} --> {alpha}{sup +}{sub 1}(1260)K*{sup 0}(892)) x B({alpha}{sup +}{sub 1}(1260) --> {pi}{sup +}{pi}{sup -}{pi}{sup +}) of 1.8 x 10{sup -6}.
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
Evidence for an excess of B -> D(*) Tau Nu decays
Based on the full BaBar data sample, we report improved measurements of the ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B -> D(*) l Nu), where l is either e or mu. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 +- 0.058 +- 0.042 and R(D*) = 0.332 +- 0.024 +- 0.018, which exceed the Standard Model expectations by 2.0 sigma and 2.7 sigma, respectively. Taken together, our results disagree with these expectations at the 3.4 sigma level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. We also report the observation of the decay B -> D Tau Nu, with a significance of 6.8 sigma.
Superallowed nuclear beta decay: Precision measurements for basic physics
For 60 years, superallowed 0{sup +}{yields}0{sup +} nuclear beta decay has been used to probe the weak interaction, currently verifying the conservation of the vector current (CVC) to high precision ({+-}0.01%) and anchoring the most demanding available test of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix ({+-}0.06%), a fundamental pillar of the electroweak standard model. Each superallowed transition is characterized by its ft-value, a result obtained from three measured quantities: the total decay energy of the transition, its branching ratio, and the half-life of the parent state. Today's data set is composed of some 150 independent measurements of 13 separate superallowed transitions covering a wide range of parent nuclei from {sup 10}C to {sup 74}Rb. Excellent consistency among the average results for all 13 transitions - a prediction of CVC - also confirms the validity of the small transition-dependent theoretical corrections that have been applied to account for isospin symmetry breaking. With CVC consistency established, the value of the vector coupling constant, G{sub V}, has been extracted from the data and used to determine the top left element of the CKM matrix, V{sub ud}. With this result the top-row unitarity test of the CKM matrix yields the value 0.99995(61), a result that sets a tight limit on possible new physics beyond the standard model. To have any impact on these fundamental weak-interaction tests, any measurement must be made with a precision of 0.1% or better - a substantial experimental challenge well beyond the requirements of most nuclear physics measurements. I overview the current state of the field and outline some of the requirements that need to be met by experimentalists if they aim to make measurements with this high level of precision.
Hardy, J. C. [Cylotron Institute, Texas A and M University, College station, TX, 77843-3366 (United States)
$?$ baryon strong decays in a chiral quark model
The strong decays of $\\Xi$ baryons up to N=2 shell were studied in a chiral quark model. The strong decay properties of these well-established ground decuplet baryons were reasonably described. We found that (i) $\\Xi(1690)$ and $\\Xi(1820)$ could be assigned to the spin-parity $J^P=1/2^-$ state $|70,^{2}{8},1,1,1/2^->$ and the spin-parity $J^P=3/2^-$ state $|70,^{2}{8},1,1,3/2^->$, respectively. Slight configuration mixing might exist in these two negative parity states. (ii) $\\Xi(1950)$ might correspond to several different $\\Xi$ resonances. The broad states ($\\Gamma\\sim 100$ MeV) observed in the $\\Xi\\pi$ channel could be classified as the pure $J^P=5/2^-$ octet state $\\Xi^0|70,^{4}8,1,1,5/2^->$ or the mixed state $|\\Xi 1/2^->_3 $ with $J^P=1/2^-$. The $\\Xi$ resonances with moderate width ($\\Gamma\\sim 60$ MeV) observed in the $\\Xi\\pi$ channel might correspond to the $J^P=1/2^+$ excitation $|56,^{4}10,2,2,1/2^+>$. The second orbital excitation $|56,^{4}10,2,2,3/2^+>$ and the mixed state $|\\Xi 1/2^->_1$ might be candidates for the narrow width state observed in the $\\Lambda \\bar{K}$ channel, however, their spin-parity numbers are incompatible with the moment analysis of the data. (iii) $\\Xi(2030)$ could not be assigned to either any spin-parity $J^P=7/2^+$ states or any pure $J^P=5/2^+$ configurations. It seems to favor the $|70,^{2}8,2,2,3/2^+>$ assignment, however, its spin conflicts with the moment analysis of the data. To find more $\\Xi$ resonances, the observations in the $\\Xi(1530)\\pi$ and $\\Sigma(1385) \\bar{K}$ channels are necessary.
Li-Ye Xiao; Xian-Hui Zhong
Inverse Beta Decay in a Nonequilibrium Antineutrino Flux from a Nuclear Reactor
The evolution of the reactor antineutrino spectrum toward equilibrium above the inverse beta-decay threshold during the reactor operating period and the decay of residual antineutrino radiation after reactor shutdown are considered. It is found that, under certain conditions, these processes can play a significant role in experiments seeking neutrino oscillations.
V. I. Kopeikin; L. A. Mikaelyan; V. V. Sinev
NEANDC specialists meeting on yields and decay data of fission product nuclides
Separate abstracts were prepared for the 29 papers presented. Workshop reports on decay heat, fission yields, beta- and gamma-ray spectroscopy, and delayed neutrons are included. An appendix contains a survey of the most recent compilations and evaluations containing fission product yield, fission product decay data, and delayed neutron yield information. (WHK)
Chrien, R.E.; Burrows, T.W. (eds.)
An experimental review of the decays of the D/sub S/ meson
In this paper I review the current experimental knowledge of the decays of the D/sub s/ meson. I compare D/sub s/ properties to those predicted from recent comprehensive D meson decay models that are based on the better measured charmed isodoublet (D/sup 0/,D/sup +/). 12 refs., 5 figs., 2 tabs.
Schindler, R.H.
Scanning delay generator for measurement of kinetic decays using laser-induced fluorescence techniques
An electronic device is described which generates a delayed pulse, where the delay is increased in a step-like manner. This device finds application in the measurement of kinetic decays, particularly when laser-induced fluorescent (LIF) detection of the decaying species is used. The circuit uses 15 low-power Schottky TTL chips and is contained within a dual width NIM module.
Halpern, J.B.; Towns, T.G.
DNS and LES of decaying isotropic turbulence with and without frame rotation using lattice Boltzmann method
The objective of the paper is to assess the effectiveness of the lattice Boltzmann equation (LBE) as a computational tool for performing direct numerical simulations (DNS) and large-eddy simulations (LES) of turbulent flows. Decaying homogeneous isotropic ... Keywords: Smagorinsky model, decaying homogeneous isotropic turbulence in 3D, direct numerical simulation, large-eddy simulation, lattice Boltzmann equation
Huidan Yu; Sharath S. Girimaji; Li-Shi Luo
Decay and storage of multiparticle entangled states of atoms in collective thermostat
We derive a master equation describing the collective decay of two-level atoms inside a single mode cavity in the dispersive limit. By considering atomic decay in the collective thermostat, we found a decoherence-free subspace of the multiparticle entangled states of the W-like class. We present a scheme for writing and storing these states in collective thermostat.
Basharov, A. M.; Gorbachev, V. N.; Rodichkina, A. A. [Laboratory for Quantum Information and Computation, Aerospace University, St.-Petersburg 190000 Bolshaia Morskaia 67 (Russian Federation)
Characterizing time decay of bibenzyl scintillator using time correlated single photon counting
The time decay of several scintillation materials has been measured using the time correlated single photon counting method and a new organic crystal with a highly suppressed delayed light has been identified. Results comparing the light decay of the bibenzyl crystal with a xylene based detector, which is currently installed at National Ignition Facility will be presented.
Hatarik, R.; Bernstein, L. A.; Caggiano, J. A.; Carman, M. L.; Schneider, D. H. G.; Zaitseva, N. P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Wiedeking, M. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); iThemba LABS, P.O. Box 722, 7129 Somerset West (South Africa)
CP Asymmetry in the Higgs Decay into the Top Pair Due to the Stop Mixing
We investigate a potentially large CP violating asymmetry in the decay of a neutral scalar or pseudoscalar Higgs boson into the top-anti-top pair. The source of the CP nonconservation is the complex mixing in the (left-right) stop sector. One of the interesting consequence is the different rates of the Higgs boson decays into CP conjugate polarized states.
Chang, Darwin
Search for b-->u transitions in B--->DK- and D*K- decays
We report results from an updated study of the suppressed decays B--->DK- and B--->D*K- followed by D-->K+pi-, where D(*) indicates a D(*)0 or a D[over-bar] (*)0 meson, and D*-->Dpi0 or D*-->Dgamma. These decays are sensitive ...
Sciolla, Gabriella
Quantization in Classical Mechanics and Diffusion Mechanism of Alpha Decay, Proton and Cluster Radioactivity, Spontaneous Fission
Based on the Chetaev generalized theorem the Schroedinger equation as the stability condition of trajectories in classical dynamics in the presence of dissipative forces is derived. In the framework of this approach the alternative model for unified description of alpha decay, spontaneous fission, cluster and proton radioactivity and is developed. We show the possibility of the classical (without tunneling) description of radioactive decay of heavy nuclei, when the so called noise-induced transition or, in other words, the stochastic channel of radioactive decay conditioned by the Kramers diffusion mechanism is generated under certain conditions.Using the ENSDF nuclear data, we have found the parametrized solutions of the Kramers equation of the Langevin type by the Alexandrov dynamic auto-regularization method (REGN-Dubna program). These solutions describe with high-accuracy the dependences of half-life (the decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products.Verification of the inverse problem solution in the framework of the universal Kramers description of alpha decay, spontaneous fission, cluster and proton radioactivity, which based on the newest experimental data for alpha-decay of even-even superheavy nuclei (Z = 114, 116, 118), shows good coincidence of the experimental and theoretical dependences of half-life on alpha-decay energy.
Rusov, V. D.; Vlasenko, D. S.; Deliyergiyev, M. A. [Department of Theoretical and Experimental Nuclear Physics, Odessa National Polytechnic University, Odessa (Ukraine); Mavrodiev, S. Cht. [Institute for Nuclear Research and Nuclear Energy, BAS, Sofia (Bulgaria)
Quantization in Classical Mechanics and Diffusion Mechanism of Alpha Decay, Cluster Radioactivity, Spontaneous Fission
Based on the Chetaev generalized theorem the Schredinger equation as the stability condition of trajectories in classical dynamics in the presence of dissipative forces is derived. In the framework of this approach the alternative model for unified description of alpha decay, spontaneous fission, cluster radioactivity and is developed. We show the possibility of the classical (without tunneling) description of radioactive decay of heavy nuclei, when the so called noise-induced transition or, in other words, the stochastic channel of radioactive decay conditioned by the Kramers diffusion mechanism is generated under certain conditions.Using the ENSDF nuclear data, we have found the parametrized solutions of the Kramers equation of the Langevin type by the Alexandrov dynamic auto-regularization method (REGN-Dubna program). These solutions describe with high-accuracy the dependences of half-life (the decay probability) of heavy radioactive nuclei on total kinetic energy of daughter decay products.Verification of the inverse problem solution in the framework of the universal Kramers description of alpha decay, spontaneous fission, cluster radioactivity, which based on the newest experimental data for alpha-decay of even-even superheavy nuclei (Z = 114, 116, 118), shows good coincidence of the experimental and theoretical dependences of half-life on alpha-decay energy.
CDF/PUB/EXOTIC/PUBLIC/10737 Search for a Standard Model Higgs Boson Decaying Into Photons
CDF/PUB/EXOTIC/PUBLIC/10737 Search for a Standard Model Higgs Boson Decaying Into Photons at CDF) A search for the SM Higgs boson in the diphoton decay channel is reported using data corre- sponding are set on the production cross section times the H branching fraction for hypothetical Higgs boson
1 Inverse Beta Decay in a Nonequilibrium Antineutrino Flux from a Nuclear Reactor
The evolution of the reactor antineutrino spectrum toward equilibrium above the inverse beta-decay threshold during the reactor operating period and the decay of residual �?e, radiation after reactor shutdown are considered. It is found that, under certain conditions, these processes can play a significant role in experiments seeking neutrino oscillations. 1.
V. I. Kopeikin A; L. A. Mikaelyan A; V. V. Sinev A
A Diffusion Cloud Chamber Study of Very Slow Mesons. II. Beta Decay of the Muon
The spectrum of electrons arising from the decay of the negative mu meson has been determined. The muons are arrested in the gas of a high pressure hydrogen filled diffusion cloud chamber. The momenta of the decay electrons are determined from their curvature in a magnetic field of 7750 gauss. The spectrum of 415 electrons has been analyzed according to the theory of Michel.
Lederman, L. M.; Sargent, C. P.; Rinehart, M.; Rogers, K.
Problem of the decay instability of electromagnetic waves in a magnetoactive plasma
The processes of decay of transverse electromagnetic waves propagating across a constant magnetic field are considered. The possibility of using these decays for tuning the frequency of the stimulated radiation in the magnetoactive plasma of semiconductors, as well as for the diagnostics of the magnetic fields that spontaneously develop in a laser plasma is discussed.
Roslyakov, V.A.; Starostin, A.N.
Search for the Standard Model Higgs boson decaying to two W bosons at CMS
In this thesis, we search for the production of the Standard Model Higgs boson at the Large Hadron Collider, through its decay mode to two W bosons, which each in turn decay into a charged lepton and a neutrino. The Higgs ...
Xie, Si, Ph. D. Massachusetts Institute of Technology
Nuclear decay heat -the energy released by fission fragments A.A. Sonzogni and M. Herman
Nuclear decay heat - the energy released by fission fragments A.A. Sonzogni and M. Herman National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973 Decay heat is an important issue that has to be dealt with after a nuclear reactor is shut down. Following the fission of an actinide
Search for bb decay with NEMO 3 and SuperNEMO experiments
NEMO 3 is a double beta decay experiment. A part of low background data was analysed, preliminary result on bb2nu decay of 130Te obtained: T_{1/2} = 7.6 \\+- 1.5(stat) +- 0.8(syst) * 10^{20} y$. No bb0nu signal was observed: T_{1/2}^{0\
V. Vasiliev; for the NEMO 3; SuperNEMO Collaborations
Search for D0 - D0bar Mixing and Rare Charm Decays
Based on a dataset acquired by the BaBar experiment running on and near the $\\Upsilon(4S)$ resonance from 1999-2002, limits are set on the rate of $D^0$-- $\\kern 0.2em\\bar{\\kern -0.2em D}{}^0$ mixing using the decay mode $D^{*+} \\to D^0 \\pi^{+}$, followed by a semi-leptonic decay of the $D^0$. Results are compared to previous BaBar analysis using hadronic decays. We also report on a search for the flavor-changing neutral current decays $D^0 \\to e^{+} e^{-}$ ($\\mu^{+} \\mu^{-}$) and the lepton-flavor violation decays $D^0 \\to e^{\\pm} \\mu^{\\mp}$.
U. Egede; for the BABAR Collaboration
Charmless Hadronic B Decays into Vector, Axial Vector and Tensor Final States at BaBar
We present experimental measurements of branching fraction and longitudinal polarization fraction in charmless hadronic B decays into vector, axial vector and tensor final states with the final dataset of BABAR. Measurements of such kind of decays are a powerful tool both to test the Standard Model and search possible sources of new physics. In this document we present a short review of the last experimental results at BABAR concerning charmless quasi two-body decays in final states containing particles with spin 1 or spin 2 and different parities. This kind of decays has received considerable theoretical interest in the last few years and this particular attention has led to interesting experimental results at the current b-factories. In fact, the study of longitudinal polarization fraction f{sub L} in charmless B decays to vector vector (VV), vector axial-vector (VA) and axial-vector axial-vector (AA) mesons provides information on the underlying helicity structure of the decay mechanism. Naive helicity conservation arguments predict a dominant longitudinal polarization fraction f{sub L} {approx} 1 for both tree and penguin dominated decays and this pattern seems to be confirmed by tree-dominated B {yields} {rho}{rho} and B{sup +} {yields} {Omega}{rho}{sup +} decays. Other penguin dominated decays, instead, show a different behavior: the measured value of f{sub L} {approx} 0.5 in B {yields} {phi}K* decays is in contrast with naive Standard Model (SM) calculations. Several solutions have been proposed such as the introduction of non-factorizable terms and penguin-annihilation amplitudes, while other explanations invoke new physics. New modes have been investigated to shed more light on the problem.
Gandini, Paolo; /Milan U. /INFN, Milan
Study of Bbar to Xu l nubar Decays in BBbar Events Tagged by a Fully Reconstructed B-meson Decay and Determination of |V_{ub}|
We report measurements of partial branching fractions for inclusive charmless semileptonic B decays {bar B} {yields} X{sub u}{ell}{bar {nu}}, and the determination of the CKM matrix element |V{sub ub}|. The analysis is based on a sample of 467 million {Upsilon}(4S) {yields} B{bar B} decays recorded with the BABAR detector at the PEP-II e{sup +}e{sup -} storage rings. We select events in which the decay of one of the B mesons is fully reconstructed and an electron or a muon signals the semileptonic decay of the other B meson. We measure partial branching fractions {Delta}{Beta} in several restricted regions of phase space and determine the CKM element |V{sub ub}| based on four different QCD predictions. For decays with a charged lepton momentum p*{sub {ell}} > 1.0 GeV in the B meson rest frame, we obtain {Delta}{Beta} = (1.80 {+-} 0.13{sub stat.} {+-} 0.15{sub sys.} {+-} 0.02{sub theo.}) x 10{sup -3} from a maximum likelihood fit to the two-dimensional M{sub X} - q{sup 2} distribution. Here, M{sub X} refers to the invariant mass of the final state hadron X and q{sup 2} is the invariant mass squared of the charged lepton and neutrino. From this measurement we extract |V{sub ub}| = (4.31 {+-} 0.25{sub exp.} {+-} 0.16{sub theo.}) x 10{sup -3} as the arithmetic average of four results obtained from four different QCD predictions of the partial rate. We separately determine partial branching fractions for {bar B}{sup 0} and B{sup -} decays and derive a limit on the isospin breaking in {bar B} {yields} X{sub u}{ell}{bar {nu}} decays.
Lees, J.P.
Dimuon production from in-medium rho decays from QCD sum rules
We compute the dimuon-excess invariant mass distribution at the rho-meson peak in the context of relativistic heavy-ion collisions at SPS energies. The temperature, T, and chemical potential, mu, dependent parameters describing the rho-meson --its width, mass and leptonic decay constant-- are determined from finite energy QCD sum rules. Results show that the rho-meson width increases whereas its mass and leptonic decay constant decrease near the (chemical potential-dependent) critical temperature T_c(mu) for chiral symmetry restoration/quark-gluon deconfinement. As a consequence, starting from T_c(mu), for a short lived cooling the main effect is a broadening of the dimuon distribution. However, when the evolution brings the system to a lower freeze-out temperature, with the rho-meson parameters approaching their vacuum values, the dimuon distribution shows a broad peak centered at the vacuum rho-meson mass. For even lower freeze-out temperatures the peak becomes less prominent since the thermal phase space factor suppresses the distribution for larger values of the invariant dimuon mass, given that the average temperature is smaller. The dimuon distribution exhibits a non-trivial behavior with mu. For small mu values the distribution broadens with increasing mu becoming a bit steeper at low invariant masses for larger values of mu. Our results are in very good agreement with data from the NA60 Collaboration.
Alejandro Ayala; C. A. Dominguez; Luis Alberto Hernandez; M. Loewe; Ana Julia Mizher
Effect of room air recirculation delay on the decay rate of tracer gas
Effect of room air recirculation delay on the decay rate of tracer gas Effect of room air recirculation delay on the decay rate of tracer gas Title Effect of room air recirculation delay on the decay rate of tracer gas Publication Type Conference Proceedings Year of Publication 2004 Authors Kristoffersen, Astrid H., Ashok J. Gadgil, and David M. Lorenzetti Conference Name 9th International Conference on Air Distribution in Rooms - RoomVent 2004, Pagination pp 6 Date Published September 5-8, 2 Conference Location Coimbra, Portugal Abstract Tracer gas measurements are commonly used to estimate the fresh air exchange rate in a room or building. Published tracer decay methods account for fresh air supply, infiltration, and leaks in ductwork. However, the time delay associated with a ventilation system recirculating tracer back to the room also affects the decay rate. We present an analytical study of tracer gas decay in a well-mixed, mechanically-ventilated room with recirculation. The analysis shows that failing to account for delays can lead to under- or over-estimates of the fresh air supply, depending on whether the decay rate calculation includes the duct volume
Analysis of Experiments Exhibiting Time-Varying Nuclear Decay Rates: Systematic Effects or New Physics?
Since the 1930s, and with very few exceptions, it has been assumed that the process of radioactive decay is a random process, unaffected by the environment in which the decaying nucleus resides. There have been instances within the past few decades, however, where changes in the chemical environment or physical environment brought about small changes in the decay rates. But even in light of these instances, decaying nuclei that were undisturbed or un-"pressured" were thought to behave in the expected random way, subject to the normal decay probabilities which are specific to each nuclide. Moreover, any "non-random" behavior was assumed automatically to be the fault of the detection systems, the environment surrounding the detectors, or changes in the background radiation to which the detector was exposed. Recently, however, evidence has emerged from a variety of sources, including measurements taken by independent groups at Brookhaven National Laboratory, Physikalisch-Technische Bundesanstalt, and Purdue University, that indicate there may in fact be an influence that is altering nuclear decay rates, albeit at levels on the order of $10^{-3}$. In this paper, we will discuss some of these results, and examine the evidence pointing to the conclusion that the intrinsic decay process is being affected by a solar influence.
Jere H. Jenkins; Ephraim Fischbach; Peter A. Sturrock; Daniel W. Mundy
Study of flavor tagging with semi-exclusive reconstruction of b [right arrow] D(sigma)X decays
The BaBar experiment measures CP violation in the B meson system by analyzing the decays of B?B?? pairs in which one of the mesons decays into a CP eigenstate. By measuring the decay time distribution separately for B? and ...
Ptacek, Elizabeth S. (Elizabeth Sara)
Compact high resolution isobar separator for study of exotic decays
Compact high resolution isobar separator for study of Compact high resolution isobar separator for study of exotic decays A. Piechaczek 1 , V. Shchepunov 1 , H. K. Carter 1 J. C. Batchelder 1 , E. F. Zganjar 2 1 UNIRIB, Oak Ridge Associated Universities, Oak Ridge, TN 37830 2 Department of Physics & Astronomy, Louisiana State University, Baton Rouge, LA 70803 A compact isobar separator, based on the Multi-Pass-Time-of-Flight (MTOF) principle, is developed [1]. A mass resolving power (MRP) as spectrometer of 110,000 (FWHM) is achieved in Time-of-Flight spectra of N 2 molecules (no physical ion separation) after 300 laps or ToF = 9.7 ms. Operated as a separator [2], molecules of N 2 and CO with ∆M/M = 1/2500 or 10.433 MeV are separated with a Bradbury Nielsen electrostatic ion gate, and the MRP (FWHM) is about 40,000 after 120 laps. In the separator as well as in
First Observation of Cabibbo-Suppressed ?_c^0 Decays
We report the first observation of the Cabibbo-suppressed decays $\\Xi_c^0\\rightarrow \\Xi^- K^+$, $\\Xi_c^0\\ra\\Lambda K^+ K^-$ and $\\Xi_c^0\\rightarrow \\Lambda \\phi$, using a data sample of $711\\, \\mathrm{fb}^{-1}$ collected at the $\\Upsilon(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. We measure the ratios of branching fractions to be $\\frac{{\\cal B}(\\Xi_c^0\\ra \\Xi^- K^+)}{{\\cal B}(\\Xi^0_c\\ra\\Xi^-\\pi^+)}=(2.75\\pm 0.51\\pm 0.25)\\times 10^{-2}$, $\\frac{{\\cal B}(\\Xi_c^0\\ra\\Lambda K^+ K^-)}{{\\cal B}(\\Xi_c^0\\rightarrow\\Xi^- \\pi^+)}=(2.86\\pm 0.61\\pm 0.24)\\times 10^{-2}$ and $\\frac{{\\cal B}(\\Xi_c^0\\ra \\Lambda\\phi)}{{\\cal B}(\\Xi^0_c\\ra\\Xi^-\\pi^+)}=(3.43\\pm 0.58\\pm 0.32)\\times 10^{-2}$, where the first uncertainty is statistical and the second is systematic.
Belle Collaboration; R. Chistov; I. Adachi; H. Aihara; D. M. Asner; V. Aulchenko; T. Aushev; A. M. Bakich; A. Bala; V. Bhardwaj; B. Bhuyan; A. Bondar; G. Bonvicini; A. Bozek; M. Bra?ko; J. Brodzicka; T. E. Browder; V. Chekelian; A. Chen; P. Chen; B. G. Cheon; K. Chilikin; I. -S. Cho; K. Cho; V. Chobanova; Y. Choi; D. Cinabro; M. Danilov; Z. Dole�al; D. Dutta; S. Eidelman; D. Epifanov; H. Farhat; J. E. Fast; M. Feindt; T. Ferber; A. Frey; V. Gaur; N. Gabyshev; S. Ganguly; R. Gillard; Y. M. Goh; B. Golob; J. Haba; T. Hara; K. Hayasaka; H. Hayashii; Y. Horii; Y. Hoshi; W. -S. Hou; H. J. Hyun; T. Iijima; A. Ishikawa; R. Itoh; Y. Iwasaki; T. Julius; D. H. Kah; J. H. Kang; E. Kato; T. Kawasaki; H. Kichimi; C. Kiesling; D. Y. Kim; H. J. Kim; J. B. Kim; J. H. Kim; K. T. Kim; Y. J. Kim; K. Kinoshita; J. Klucar; B. R. Ko; P. Kody�; S. Korpar; P. Kri�an; T. Kumita; A. Kuzmin; Y. -J. Kwon; J. S. Lange; S. -H. Lee; J. Li; Y. Li; J. Libby; C. Liu; Y. Liu; D. Liventsev; P. Lukin; D. Matvienko; H. Miyata; R. Mizuk; G. B. Mohanty; A. Moll; T. Mori; N. Muramatsu; R. Mussa; E. Nakano; M. Nakao; Z. Natkaniec; M. Nayak; E. Nedelkovska; C. Ng; S. Nishida; O. Nitoh; S. Ogawa; S. Okuno; S. L. Olsen; C. Oswald; G. Pakhlova; C. W. Park; H. Park; H. K. Park; R. Pestotnik; M. Petri?; L. E. Piilonen; M. Ritter; M. R�hrken; A. Rostomyan; H. Sahoo; T. Saito; K. Sakai; Y. Sakai; S. Sandilya; D. Santel; L. Santelj; T. Sanuki; V. Savinov; O. Schneider; G. Schnell; C. Schwanda; D. Semmler; K. Senyo; O. Seon; M. E. Sevior; M. Shapkin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; B. Shwartz; A. Sibidanov; F. Simon; Y. -S. Sohn; A. Sokolov; E. Solovieva; M. Stari?; M. Steder; M. Sumihama; T. Sumiyoshi; U. Tamponi; K. Tanida; G. Tatishvili; Y. Teramoto; M. Uchida; T. Uglov; Y. Unno; S. Uno; P. Urquijo; Y. Usov; S. E. Vahsen; C. Van Hulse; P. Vanhoefer; G. Varner; K. E. Varvell; A. Vinokurova; M. N. Wagner; C. H. Wang; M. -Z. Wang; P. Wang; X. L. Wang; Y. Watanabe; K. M. Williams; E. Won; B. D. Yabsley; J. Yamaoka; Y. Yamashita; S. Yashchenko; Y. Yook; Y. Yusa; Z. P. Zhang; V. Zhilich; V. Zhulanov; A. Zupanc
Extracting bb Higgs Decay Signals using Multivariate Techniques
For low-mass Higgs boson production at ATLAS at {radical}s = 7 TeV, the hard subprocess gg {yields} h{sup 0} {yields} b{bar b} dominates but is in turn drowned out by background. We seek to exploit the intrinsic few-MeV mass width of the Higgs boson to observe it above the background in b{bar b}-dijet mass plots. The mass resolution of existing mass-reconstruction algorithms is insufficient for this purpose due to jet combinatorics, that is, the algorithms cannot identify every jet that results from b{bar b} Higgs decay. We combine these algorithms using the neural net (NN) and boosted regression tree (BDT) multivariate methods in attempt to improve the mass resolution. Events involving gg {yields} h{sup 0} {yields} b{bar b} are generated using Monte Carlo methods with Pythia and then the Toolkit for Multivariate Analysis (TMVA) is used to train and test NNs and BDTs. For a 120 GeV Standard Model Higgs boson, the m{sub h{sup 0}}-reconstruction width is reduced from 8.6 to 6.5 GeV. Most importantly, however, the methods used here allow for more advanced m{sub h{sup 0}}-reconstructions to be created in the future using multivariate methods.
Smith, W Clarke; /George Washington U. /SLAC
Kinetic dispersion of Langmuir waves. I. The Langmuir decay instability
We derive a fully kinetic, three-dimensional dispersion relation for Langmuir waves with a focus on the Langmuir decay instability (LDI). The kinetic dispersion is compared to the standard fluid dispersion found with an equation of state (EOS) closure. The EOS closure fails to capture the intricacies of the nonlinear pressure when high frequency electron plasma waves (EPWs) couple to low frequency ion acoustic waves (IAWs). In particular, we find discrepancies in the k{lambda}{sub d} scaling of the LDI growth rate, where k is the wavenumber of the incident EPW and {lambda}{sub d} is the Debye length. As a result, the kinetic dispersion relation for LDI results in instability thresholds that can be in excess of twice those predicted by the fluid theory. Both the fluid and kinetic dispersion relations predict a nonlinear frequency shift due to the beating of the pump and scattered EPWs, but again the k{lambda}{sub d} scaling of these frequency shifts differ. In addition, the kinetic dispersion predicts a nonlinear reduction in the IAW damping from the three-wave interaction.
Palastro, J. P.; Williams, E. A.; Hinkel, D. E.; Divol, L.; Strozzi, D. J. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)
Electret-based passive air samplers have been used in United Kingdom and elsewhere for quantitative sampling for airborne dust. Alpha electret ion chambers (EIC) have been used for quantitative measurement of deposited alpha emitting isotopes. These two well documented principles are combined to create a passive radon progeny monitor. Large area (50 cm2) electret charged to 500 to 2000 volts collect airborne radon decay products and the collected sample is "viewed " and measured by an alpha EIC. Such collection and measurement continues for the entire period of sampling, providing an integrated signal to the electret in alpha EIC. The present work is of exploratory nature and provides the responses of three different sizes of collection electrets. Results are also compared with a simple passive device with no collecting electret. The study provides data for optimization of the design depending upon the requirement. Study is limited to a typical home with equilibrium ratios from 40 to 60%. This method can be used for both short term and long term monitoring of RDP in working level units.
F. Stieff
Measurement of the polarization amplitudes of the Bs -> PhiPhi decay at CDF II
In this thesis we present the first measurement of the polarization amplitudes for the charmless B{sub s} {yields} {phi}{phi} {yields} [K{sup +}K{sup -}][K{sup +}K{sup -}] decay of the B{sub s} meson. The result is achieved using an unbinned Maximum Likelihood fit to the data collected by the Collider Detector at Fermilab (CDF) in Run II (CDFII), in a period starting from March 2001 till April 2008, which corresponds to an integrated luminosity of 2.9 fb{sup -1}. The resulting yield consists of 300 signal events selected by the Two Track Trigger (TTT). Furthermore, our work puts in evidence an original topic, that was never observed until now: an unexpected dependence of the signal acceptance on the proper decay time (t) of the B{sub s} mesons. This specific issue, which is most likely a general feature induced by any signal selection based on the lifetime information, is supposed to be related to the on-line TTT and off-line selections based on the impact parameter. The involved fit, indeed, reproduces the biases observed in large statistics Monte Carlo (MC) samples. The thesis presents the same analysis performed for the B{sub s}{sup 0} {yields} J{psi}{phi} decay as well, which is used as a control sample. The polarizations amplitudes we find are consistent with the published ones; this result contributes to enforce the reliability of the analysis. This work is considered ready to begin the procedure for official approval by the CDF collaboration pending the finalization of the systematic uncertainty which has not yet been fully completed.
Dorigo, Mirco; /Trieste U. /INFN, Trieste
Nuclear Decay Data in the MIRD (Medical Internal Radiation Dose) Format
DOE Data Explorer (OSTI)
MIRD is a database of evaluated nuclear decay data for over 2,100 radioactive nuclei. Data are extracted from ENSDF, processed by the program RadList, and used for medical internal radiation dose calculations. When using the MIRD interface, tables of nuclear and atomic radiations from nuclear decay and decay scheme drawings will be produced in the MIRD format from the Evaluated Nuclear Structure Data File (ENSDF) for the specified nuclide. Output may be either HTML-formatted tables and JPEG drawings, PostScript tables and drawings, or PDF tables and drawings.
Unburied Higgs boson: Jet substructure techniques for searching for Higgs' decay into gluons
Many models of physics beyond the standard model yield exotic Higgs decays. Some of these, particularly those in which the Higgs decays to light quarks or gluons, can be very difficult to discover experimentally. Here we introduce a new set of jet substructure techniques designed to search for such a Higgs when its dominant decay is into gluons via light, uncolored resonances. We study this scenario in both V+h and tt+h production channels, and find both channels lead to discovery at the LHC with > or approx. 5{sigma} at L{approx}100 fb{sup -1}.
Falkowski, Adam; Krohn, David; Wang Liantao; Shelton, Jessie; Thalapillil, Arun [NHETC and Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08854 (United States); Department of Physics, Princeton University, Princeton, New Jersey 08540 (United States); Department of Physics, Yale University, New Haven, Connecticut 06511 (United States); EFI and Department of Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, Illinois 60637 (United States)
Measuring the Higgs boson mass in dileptonic W-boson decays at hadron colliders
ar X iv :0 90 2. 48 64 v2 [ he p- ph ] 22 Ju l 2 00 9 Cavendish-HEP-09/04 Measuring the Higgs boson mass in dileptonic W -boson decays at hadron colliders Alan J. Barr,1, ? Ben Gripaios,2, � and Christopher G. Lester3, � 1Denys Wilkinson... measurements of the Higgs boson mass using the decay h ? W+W?, followed by the leptonic decay of each W -boson, will be performed by fitting the shape of a distribution that is sensitive to the Higgs mass. We demonstrate that the variable most commonly used...
Barr, Alan; Gripaios, Ben; Lester, Christopher G
Probing the three-Higgs-boson coupling in heavy-quarkonium decays
We calculate (in the context of the standard model) the rate for radiative decay of a heavy-quark--antiquark /sup 3/S/sub 1/ bound state into Higgs-boson pairs, i.e., GAMMA(V-italic..-->..H-italicH-italic..gamma..). This process has contributions from diagrams containing the three-Higgs-boson self-coupling. We investigate whether that coupling is measurable in decays of the t-italic-quarkonium system or a hypothetical, heavy, fourth-generation b-italic'-quarkonium. We also briefly discuss the prospects for measuring such trilinear Higgs-boson couplings in heavy-quarkonium decays for two-Higgs-doublet theories.
Golowich, E.; Robinett, R.W.
Observation of Two-Neutrino Double-Beta Decay in Xe-136 with EXO-200
We report the observation of two-neutrino double-beta decay in {sup 136}Xe with T{sub 1/2} = 2.11 {+-} 0.04(stat) {+-} 0.21(syst) x 10{sup 21} yr. This second-order process, predicted by the standard model, has been observed for several nuclei but not for {sup 136}Xe. The observed decay rate provides new input to matrix element calculations and to the search for the more interesting neutrinoless double-beta decay, the most sensitive probe for the existence of Majorana particles and the measurement of the neutrino mass scale.
Ackerman, N.; /SLAC; Aharmim, B.; /Laurentian U.; Auger, M.; /Bern U.; Auty, D.J.; /Alabama U.; Barbeau, P.S.; Barry, K.; Bartoszek, L.; /Stanford U., Phys. Dept.; Beauchamp, E.; /Laurentian U.; Belov, V.; /Moscow, ITEP; Benitez-Medina, C.; /Colorado State U.; Breidenbach, M.; /SLAC; Burenkov, A.; /Moscow, ITEP; Cleveland, B.; /Laurentian U.; Conley, R.; Conti, E.; /SLAC; Cook, J.; /Massachusetts U., Amherst; Cook, S.; /Colorado State U.; Coppens, A.; /Carleton U.; Counts, I.; /Stanford U., Phys. Dept.; Craddock, W.; /SLAC; Daniels, T.; /Massachusetts U., Amherst /Moscow, ITEP /Maryland U. /Stanford U., Phys. Dept. /Alabama U. /Maryland U. /Moscow, ITEP /Stanford U., Phys. Dept. /Laurentian U. /Carleton U. /Colorado State U. /Laurentian U. /Munich, Tech. U. /Bern U. /SLAC /Bern U. /Carleton U. /Stanford U., Phys. Dept. /Carleton U. /Maryland U. /Colorado State U. /SLAC /Carleton U. /SLAC /Alabama U. /SLAC /Moscow, ITEP /Indiana U. /Stanford U., Phys. Dept. /Moscow, ITEP /Stanford U., Phys. Dept. /Massachusetts U., Amherst /Seoul U. /Carleton U. /Stanford U., Phys. Dept.; /more authors..
238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc
Open Energy Info (EERE)
238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc 238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: 238U Decay Series Systematics Of Young Lavas From Batur Volcano, Sunda Arc Details Activities (0) Areas (0) Regions (0) Abstract: Activities of 238U decay series radioisotopes have been determined for both postcaldera basalts erupted between 1849 and 1974 and genetically related young precaldera dacites from Batur volcano, Bali, Sunda arc. All rocks possess (230Th/238U) = 1 within 2 sigma error indicating that little, if any, fractionation between Th and U occurred during their genesis, or in their source regions, within approximately the last 350 ka. Both the basaltic and the dacitic rocks possess (230Th/232U) ~
Experimental study of double-{beta} decay modes using a CdZnTe detector array
An array of sixteen 1 cm{sup 3} CdZnTe semiconductor detectors was operated at the Gran Sasso Underground Laboratory (LNGS) to further investigate the feasibility of double-{beta} decay searches with such devices. As one of the double-{beta} decay experiments with the highest granularity the 4x4 array accumulated an overall exposure of 18 kg days. The setup and performance of the array is described. Half-life limits for various double-{beta} decay modes of Cd, Zn, and Te isotopes are obtained. No signal has been found, but several limits beyond 10{sup 20} years have been performed. They are an order of magnitude better than those obtained with this technology before and comparable to most other experimental approaches for the isotopes under investigation. An improved limit for the {beta}{sup +}/EC decay of {sup 120}Te is given.
Dawson, J. V. [Laboratoire Astroparticule et Cosmologie, 10 rue Alice Domon et Leonie Duquet, F-75205 Paris (France); Goessling, C.; Koettig, T.; Muenstermann, D.; Rajek, S.; Schulz, O. [Lehrstuhl fuer Experimentelle Physik IV, Technische Universitaet Dortmund, Otto-Hahn Str. 4, D-44227 Dortmund (Germany); Janutta, B.; Zuber, K. [Institut fuer Kern- und Teilchenphysik, Technische Universitaet Dresden, Zellescher Weg 19, D-01069 Dresden (Germany); Junker, M. [Laboratori Nazionali del Gran Sasso, Assergi (Italy); Reeve, C. [University of Sussex, Falmer, Brighton BN1 9QH (United Kingdom); Wilson, J. R. [University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom)
Chemical and Charge Imbalance Induced by Radionuclide Decay: Effects on Waste Form Structure
This is a milestone document covering the activities to validate theoretical calculations with experimental data for the effect of the decay of 90Sr to 90Zr on materials properties. This was done for a surragate waste form strontium titanate.
Van Ginhoven, Renee M.; Jaffe, John E.; Jiang, Weilin; Strachan, Denis M.
Lepton Universality, |V(Us)| and Search for Second Class Current in Tau Decays
Several hundred million {tau} decays have been studied with the BABAR detector at the PEP-II e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. Recent results on Charged Current Lepton Universality and two independent measurements of |V{sub us}| using {tau}{sup -} {yields} e{sup -}{bar {nu}}{sub e}{nu}{sub {tau}}, {mu}{sup -}{bar {nu}}{sub {mu}}{nu}{sub {tau}}, {pi}{sup -}{nu}{sub {tau}}, K{sup -} {nu}{sub {tau}} and K{sub S}{sup 0}{pi}{sup -} {nu}{sub {tau}} decays, and a search for Second Class Current in {tau}{sup -} {yields} {pi}{sup -} {omega}{nu}{sub {tau}} decays are presented, where the charge conjugate decay modes are also implied.
Banerjee, Swagato; /Victoria U.
Decay of the Loschmidt echo in a time-dependent environment
We study the decay rate of the Loschmidt echo or fidelity in a chaotic system under a time-dependent perturbation $V(q,t)$ with typical strength $\\hbar/\\tau_{V}$. The perturbation represents the action of an uncontrolled environment interacting with the system, and is characterized by a correlation length $\\xi_0$ and a correlation time $\\tau_0$. For small perturbation strengths or rapid fluctuating perturbations, the Loschmidt echo decays exponentially with a rate predicted by the Fermi Golden Rule, $1/\\tilde{\\tau}= \\tau_{c}/\\tau_{V}^2$, where typically $\\tau_{c} \\sim \\min[\\tau_{0},\\xi_0/v]$ with $v$ the particle velocity. Whenever the rate $1/\\tilde{\\tau}$ is larger than the Lyapunov exponent of the system, a perturbation independent Lyapunov decay regime arises. We also find that by speeding up the fluctuations (while keeping the perturbation strength fixed) the fidelity decay becomes slower, and hence, one can protect the system against decoherence.
Fernando M. Cucchietti; Caio H. Lewenkopf; Horacio M. Pastawski
A Single Continuous Function as a Model for Fast Rise Exponential Decay Gamma-Ray Bursts.
??A quantitative analysis was performed on a sample of Fast-Rise Exponential-Decay gamma-ray bursts using a continuous fitting function. The data were obtained from the Large� (more)
Logue, Daniel B
Beta-decay spectroscopy relevant to the r-process nucleosynthesis
A scientific program of beta-decay spectroscopy relevant to r-process nucleosynthesis has been started using high intensity U-beam at the RIBF. The first results of {beta}-decay half-lives of very neutron-rich Kr to Tc nuclides, all of which lie close to the r-process path, suggest a systematic enhancement of the the {beta}-decay rates of the Zr and Nb isotopes around A110 with respect to the predictions of the deformed quasiparticle-random-phase-approximation model (FRDM + QRPA). An impact of the results on the astrophysical r-process is discussed together with the future perspective of the {beta}-decay spectroscopy with the EURICA.
Nishimura, Shunji [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Collaboration: RIBF Decay Collaboration
Analysis of an esoteric interpretation of a threshold in beta decay
A threshold associated with a small mixing of a heavy neutrino in beta decay cannot be interpreted as due to the production of a fictitious neutral scalar in conjunction with a light neutrino.
Karl, G.; Novikov, V.; Simpson, J.J. (Department of Physics, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada))
Modeling Minority-Carrier Lifetime Techniques That Use Transient Excess-Carrier Decay: Preprint
Lifetime spectroscopy is a valuable tool for the characterization of PV materials. This paper combines modeling and experimental results to illustrate the injection-level dependent response of three transient excess-carrier decay techniques.
Johnston, S. W.; Berman, G. M.; Ahrenkiel, R. K.
Investigation of Wave Growth and Decay in the SWAN Model: Three Regional-Scale Applications
Wave growth and decay characteristics in a typical wave action model [Simulating Waves Nearshore (SWAN)] are investigated in this paper. This study is motivated by generally poor agreement between model results and measurements for a regional-...
W. Erick Rogers; Paul A. Hwang; David W. Wang
Fundamental processes in the interacting boson model: 0{nu}{beta}{beta} decay
A program to calculate nuclear matrix elements for fundamental processes in the interacting boson model has been initiated. Results for the nuclear matrix elements in neutrinoless double beta decay 0{nu}{beta}{beta} are presented.
Iachello, F. [Center for Theoretical Physics, Sloane Physics Laboratory, Yale University, New Haven, CT 06520-8120 (United States); Barea, J. [Departamento de Fisica, Universidad de Concepcion, Casilla 160-C, Concepcion (Chile)
Relativistic calculation of the two-photon decay rate of highly-excited ionic states
Based on quantum electrodynamics, we reexamine the two-photon decay of one-electron atoms. Special attention is paid to the calculation of the (two-photon) total decay rates which can be viewed as the imaginary part of the two-loop self-energy. We argue that our approach can easily be applied to the cases with a virtual state having an intermediate energy between the initial and the final state of the decay process leading, thus, to the resonance peaks in the two-photon energy distribution. In order to illustrate our approach, we obtain fully relativistic results, resolved into electric and magnetic multipole components, for the two-photon decay rates of the 3S_{1/2} -> 1S_{1/2} transition in neutral hydrogen as well as in various hydrogen-like ions.
Jentschura, Ulrich D
Two Regimes of Laboratory Whitecap Foam Decay: Bubble-Plume Controlled and Surfactant Stabilized
A laboratory experiment to quantify whitecap foam decay time in the presence or absence of surface active material is presented. The investigation was carried out in the glass seawater channel at the Hydraulics Facility of Scripps Institution of ...
Adrian H. Callaghan; Grant B. Deane; M. Dale Stokes
Using NERSC Systems, Physcists Close in on a Rare-Particle Decay...
the wall at both ends of the cylinder. To shield it from cosmic rays and other background radiation that may contaminate the signal of such a decay, the apparatus is buried deep...
Limits on tau lepton-flavor violating decays into three charged leptons
A search for the neutrinoless, lepton-flavor violating decay of the ? [tau] lepton into three charged leptons has been performed using an integrated luminosity of 468??fb-1 [fb superscript -1] collected with the BABAR ...
Back-to-Back Black Holes decay Signature at Neutrino Observatories
We propose a decay signature for non-thermal small black holes with masses in the TeV range which can be discovered by neutrino observatories. The black holes would result due to the impact between ultra high energy neutrinos with nuclei in water or ice and decay instantaneously. They could be produced if the Planck scale is in the few TeV region and the highly energetic fluxes are large enough. Having masses close to the Planck scale, the typical decay mode for these black holes is into two particles emitted back-to-back. For a certain range of angles between the emitted particles and the center of mass direction of motion, it is possible for the detectors to measure separate muons having specific energies and their trajectories oriented at a large enough angle to prove that they are the result of a back-to-back decay event.
Nicusor Arsene; Xavier Calmet; Lauretiu Ioan Caramete; Octavian Micu
NMSSM Higgs Detection: LHC, LC, $\\gam C$ Collider Complementarity and Higgs-to-Higgs Decays
We discuss the importance of being able to detect Higgs-to-Higgs-pair decays in the context of the Next-to-Minimal Supersymmetric Model (NMSSM) and demonstrate the excellent capabilities of a photon collider for this purpose.
John F. Gunion; Michal Szleper
Design of passive decay heat removal system for the lead cooled flexible conversion ratio fast reactor
The lead-cooled flexible conversion ratio fast reactor shows many benefits over other fast-reactor designs; however, the higher power rating and denser primary coolant present difficulties for the design of a passive decay ...
Whitman, Joshua (Joshua J.)
Higgs boson decay into heavy quarks and heavy leptons: higher order corrections
Theoretical predictions for the decay width of Standard Model Higgs boson into bottom quarks and tau-leptons, in the case when M_HHiggs boson into bb and tau+tau- are discussed.
Kim, Victor T
A Simple Empirical Model for Predicting the Decay of Tropical Cyclone Winds after Landfall
An empirical model for predicting the maximum wind of landfalling tropical cyclones is developed. The model is based upon the observation that the wind speed decay rate after landfall is proportional to the wind speed. Observations also indicate ...
John Kaplan; Mark DeMaria
Effects of W/sub R/ and charged Higgs in the leptonic decay of /tau/
Experimental test of the existence of the right-hand W boson and the charged Higgs particle is suggested. The experiment involves measurement of muon polarization from the decay of polarized /tau/'s. 8 refs., 2 figs., 1 tab.
Tsai, Yung Su
Observation of B?s - B??s oscillations using partially reconstructed hadronic Bs decays
This thesis describes the contribution of partially reconstructed hadronic decays in the world's first observation of B?s - B??s oscillations. The analysis is a core member of a suite of closely related studies whose ...
Miles, Jeffrey Robert
CP violation in flavor-tagged Bs? --> J/[psi][phi] decays
In this dissertation, we present the results of a time-dependent angular analysis of Bs -+ J/,0 decays performed with the use of initial-state flavor tagging. CP violation is observed in this mode through the interference ...
Makhoul, Khaldoun
Decaying Singular Vectors and Their Impact on Analysis and Forecast Correction
The full set of kinetic energy singular values and singular vectors for the forward tangent propagator of a quasigeostrophic potential vorticity model is examined. In contrast to the fastest growing singular vectors, the fastest decaying vectors ...
C. A. Reynolds; T. N. Palmer
Search for the Standard Model Higgs boson in the fully leptonic WW decay channel at CMS.
??A search for the Standard Model Higgs boson decaying to W?W? is presented. Data is taken from pp collisions with center of mass energy sqrt(s)� (more)
LeBourgeois, Matthew
Soliton formation and saturation of decay instability of an electromagnetic wave into two plasma waves
The soliton formation with its detuning of the resonance is shown to be an important saturation mechanism for the two-plasmon decay instability at the quarter critical density in laser-irradiated plasmas.
Chen, H.H.; Liu, C.S.
Evidence against correlations between nuclear decay rates and Earth-Sun distance
distance of the source to the Sun. This work was supportedNuclear Decay Rates and Earth-Sun Distance Eric B. Normanand 241 Am and the Earth-Sun distance. We find no evidence
Norman, Eric B.
Equatorial Jets in Decaying Shallow-Water Turbulence on a Rotating Sphere
Ensemble experiments of decaying shallow-water turbulence on a rotating sphere are performed to confirm the robustness of the emergence of an equatorial jet. While previous studies have reported that the equatorial jets emerging in shallow-water ...
Yuji Kitamura; Keiichi Ishioka
Use of uranium decay series for dating an archaeological smelting site
Through the identification of phases and their isotopic composition and variability, an assessment of the applicability of uranium decay series dating to El Manchon slags was made. El Manchon is the only Mesoamerican site ...
Wolf, Violetta (Violetta R.)
Different Pacific Ocean Warming Decaying Types and Northwest Pacific Tropical Cyclone Activity
This study focuses on statistical analysis of anomalous TC activities and the physical mechanisms behind these anomalies. Different patterns of decaying of the warm sea surface temperature anomaly (SSTA) over the equatorial central-eastern Pacific ...
Yao Ha; Zhong Zhong; Xiuqun Yang; Yuan Sun
Study of the tau- ---> 3h- 2h+ tau-neutrino decay
The branching fraction of the {tau}{sup -} {yields} 3h{sup -} 2h{sup +} {nu}{sub {tau}} decay (h = {pi}, K) is measured with the BABAR detector to be (8.56 {+-} 0.05 {+-} 0.42) x 10{sup -4}, where the first error is statistical and the second systematic. The observed structure of this decay is significantly different from the phase space prediction, with the {rho} resonance playing a strong role. The decay {tau}{sup -} {yields} f{sub 1}(1285){pi}{sup -}{nu}{sub {tau}}, with the f{sub 1}(1285) meson decaying to four charged pions, is observed and the branching fraction is measured to be (3.9 {+-} 0.7 {+-} 0.5) x 10{sup -4}.
Aubert, B.; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; /Annecy, LAPP; Grauges, E.; /Barcelona, IFAE; Palano, A.; Pappagallo, M.; Pompili, A.; /Bari U. /INFN, Bari; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; /Beijing, Inst. High Energy Phys.; Eigen, G.; Ofte, I.; Stugu, B. /Bergen U. /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /Padua U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /Perugia U. /INFN, Perugia /Pisa U. /INFN, Pisa /Prairie View A-M /Princeton U. /Rome U. /INFN, Rome /Rostock U. /Rutherford /DAPNIA, Saclay /South Carolina U. /SLAC /Oregon U. /SLAC /SLAC /Stanford U., Phys. Dept. /SUNY, Stony Brook /Tennessee U. /Texas U. /Texas U., Dallas /Turin U. /INFN, Turin /Trieste U. /INFN, Trieste /Valencia U., IFIC /Vanderbilt U. /Victoria U. /Warwick U. /Wisconsin U., Madison /Yale U.
Improved Measurement of CP Observables in B- to D0_CP K- Decays
We present a study of the decay B{sup -} {yields} D{sub (CP)}{sup 0}K{sup -} and its charge conjugate, where D{sub (CP)}{sup 0} is reconstructed in both a non-CP flavor eigenstate and in CP (CP-even and CP-odd) eigenstates, based on a sample of 382 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring. We measure the direct CP asymmetries A{sub CP{+-}} and the ratios of the branching fractions R{sub CP{+-}}: A{sub CP+} = 0.27 {+-} 0.09(stat) {+-} 0.04(syst), A{sub CP-} = -0.09 {+-} 0.09(stat) {+-} 0.02(syst), R{sub CP+} = 1.06 {+-} 0.10(stat) {+-} 0.05(syst), R{sub CP-} = 1.03 {+-} 0.10(stat) {+-} 0.05(syst). These results will help to better constrain the gamma phase parameter of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.
Aubert, Bernard; Bona, Marcella; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Lopez, L.; Palano, Antimo; Pappagallo, M.; /INFN, Bari; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Abrams, G.S.; Battaglia, Marco; Brown, D.N.; Button-Shafer, Janice; Cahn, Robert N.; /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /INFN, Pisa /Princeton U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison
Equilibration of anisotropic quark-gluon plasma produced by decays of color flux tubes
A set of kinetic equations is used to study equilibration of the anisotropic quark-gluon plasma produced by decays of color flux tubes possibly created at the very early stages of ultra-relativistic heavy-ion collisions. The decay rates of the initial color fields are given by the Schwinger formula, and the collision terms are treated in the relaxation-time approximation. By connecting the relaxation time with viscosity we are able to study production and thermalization processes in the plasma characterized by different values of the ratio of the shear viscosity to entropy density, eta/s. For the lowest (KSS) value of this ratio, 4 pi eta/s = 1, and realistic initial conditions for the fields, the system approaches the viscous-hydrodynamics regime within 1-2 fm/c. On the other hand, for larger values of the viscosity, 4 pi eta/s greater or equal to 3, the collisions in the plasma become inefficient to destroy collective phenomena which manifest themselves as oscillations of different plasma parameters. The presence of such oscillations brings in differences between the kinetic and hydrodynamic descriptions, which suggest that the viscous-hydrodynamics approach after 1-2 fm/c is not complete if 4 pi eta/s is greater or equal to 3 and should be extended to include dissipative phenomena connected with color conductivity.
Radoslaw Ryblewski; Wojciech Florkowski
{sigma} meson exchange effect on non-mesonic hypernuclear weak decay observables
We analyze the influence of {sigma} meson exchange on the main non-mesonic hypernuclear weak decay observables: Total rate {gamma}{sub NM}, neutron-to-proton branching ratio {gamma}{sub n/p}, and proton asymmetry parameter a{sub {lambda}}. The {sigma} meson exchange is added to the standard strangeness-changing weak {lambda}N{yields}NN transition potential, which includes the exchange of the complete pseudoscalar and vector mesons octet ({pi},{eta},K,{rho},{omega},K{sup *}). Using a shell model formalism, the {sigma} meson weak coupling constants are adjusted to reproduce the recent {gamma}{sub NM} and {gamma}{sub n/p} experimental data for {sub {lambda}}{sup 5}He. Numerical results for the remaining observables of {sub {lambda}}{sup 5}He and all the observables of {sub {lambda}}{sup 12}C decays are presented. They clearly show that the addition of the {sigma} meson improves the agreement with the data. However, its effect it is not enough to reproduce well the a{sub {lambda}} values, which means that other improvements of the model must be explored to explain the puzzle posed by the experiments.
Barbero, C.; Mariano, A. [Departamento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 67, 1900 La Plata (Argentina)
Simulation free measurement of the B+ lifetime using decays selected using displaced tracks
The lifetime of the B{sup {+-}} meson is measured using the decay channel B{sup +} {yields} {bar D}{sup 0}{pi}{sup +}. The measurement is made using approximately 1.0 fb{sup -1} of Tevatron proton-anti-proton collision data at {radical}s = 1.96 TeV collected by the CDF detector. The data were collected using impact parameter based triggers that were designed to select events with a secondary vertex. The trigger selection criteria result in data rich in a variety of B hadron decays, but intrinsically bias the lifetime distribution of the collected signal events. The traditional way to compensate for the bias is to use information from simulation. Presented here is a new method for correction of the lifetime bias using an analytical technique that uses information from the data only. This eliminates measurement uncertainty due to data and simulation agreement, ultimately resulting in a smaller systematic measurement uncertainty. The B{sup {+-}} lifetime measurement is the first measurement using this new technique and demonstrates its potential for use in future measurements. The B{sup {+-}} lifetime is measured to be {tau}(B{sup {+-}}) = 1.662 {+-} 0.023(stat) {+-} 0.015(syst)ps.
Malde, Sneha; /Oxford U.
A new limit on the CP violating decay KS -> 3pi0 with the KLOE experiment
We have carried out a new direct search for the CP violating decay KS -> 3pi0 with 1.7 fb^-1 of e+e- collisions collected by the KLOE detector at the phi-factory DAFNE. We have searched for this decay in a sample of about 5.9 x 10^8 KS KL events tagging the KS by means of the KL interaction in the calorimeter and requiring six prompt photons. With respect to our previous search, the analysis has been improved by increasing of a factor four the tagged sample and by a more effective background rejection of fake KS tags and spurious clusters. We find no candidates in data and simulated background samples, while we expect 0.12 standard model events. Normalizing to the number of KS -> 2pi0 events in the same sample, we set the upper limit on BR(KS -> 3pi0 < 2.6 x 10^-8 at 90% C.L., five times lower than the previous limit. We also set the upper limit on the eta_000 parameter, |eta_000 | < 0.0088 at 90% C.L., improving by a factor two the latest direct measurement.
Babusci, D; Balwierz-Pytko, I; Bencivenni, G; Bini, C; Bloise, C; Bossi, F; Branchini, P; Budano, A; Balkestahl, L Caldeira; Capon, G; Ceradini, F; Ciambrone, P; Curciarello, F; Czerwinski, E; Dane, E; De Leo, V; De Lucia, E; De Robertis, G; De Santis, A; Di Domenico, A; Di Donato, C; Di Salvo, R; Domenici, D; Erriquez, O; Fanizzi, G; Fantini, A; Felici, G; Fiore, S; Franzini, P; Gauzzi, P; Giardina, G; Giovannella, S; Gonnella, F; Graziani, E; Happacher, F; Heijkenskjold, L; Hoistad, B; Iafolla, L; Jacewicz, M; Johansson, T; Kacprzak, K; Kupsc, A; Lee-Franzini, J; Leverington, B; Loddo, F; Loffredo, S; Mandaglio, G; Martemianov, M; Martini, M; Mascolo, M; Messi, R; Miscetti, S; Morello, G; Moricciani, D; Moskal, P; Nguyen, F; Passeri, A; Patera, V; Longhi, I Prado; Ranieri, A; Redmer, C F; Santangelo, P; Sarra, I; Schioppa, M; Sciascia, B; Silarski, M; Taccini, C; Tortora, L; Venanzoni, G; Wislicki, W; Wolke, M; Zdebik, J
Study of B-Meson Decays to Final States with a Single Charm Baryon
A study of B-meson decays to final states with a single charm baryon is presented based on data recorded by the BABAR detector at the Stanford Linear Accelerator Center. Although the B meson is the lightest bottom-flavored meson, it is heavy enough to decay to a baryon made of three quarks and an antibaryon made of three antiquarks. By studying the baryonic weak decays of the B meson, we can investigate baryon production mechanisms in heavy meson decays. In particular, we measure the rates of the decays B{sup -} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup -} and {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}. Comparing these rates, we confirm an observed trend in baryonic B decays that the decay with the lower energy release, B{sup -} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup -}, is favored over {bar B}{sup 0} {yields} {Lambda}{sub c}{sup +}{bar p}. The dynamics of the baryon-antibaryon ({Lambda}{sub c}{sup +}{bar p}) system in the three-body decay also provide insight into baryon-antibaryon production mechanisms. The B{sup -} {yields} {Lambda}{sub c}{sup +}{bar p}{pi}{sup -} system is a laboratory for searches for excited {Sigma}{sub c} baryon states; we observe the resonant decays B{sup -} {yields} {Sigma}{sub c}(2455){sup 0}{bar p} and B{sup -} {yields} {Sigma}{sub c}(2800){sup 0}{bar p}. This is the first observation of the decay B{sup -} {yields} {Sigma}{sub c}(2800){sup 0}{bar p}; however, the mass of the observed {Sigma}{sub c}(2800){sup 0} state is inconsistent with previous measurements. Finally, we examine the angular distribution of the B{sup -} {yields} {Sigma}{sub c}(2455){sup 0}{bar p} decays and measure the spin of the {Sigma}{sub c}(2455){sup 0} baryon to be J = 1/2, as predicted by the quark model.
Majewski, Stephanie A.; /SLAC
Ratio of D/sup 0/ and D/sup +/ lifetimes from their semileptonic decays
The conventional expectation for the decays of D mesons assumes that the charm quark decays in the presence of light, spectator quarks and thus the lifetimes of both charged and uncharged states are equal. In this article, evidence is presented from DELCO (at SPEAR) that the D lifetimes are quite different for neutral and charged mesons, and the results which have also become available from other experiments are reviewed.
Donaldson, G.J.
arXiv:hepex/0101043 Search for the radiative decay j !
energy limit. Therefore it is not surprising that the last chapter of our theoretical history is related Introduction The experimental history of the j ! �? 0 flfl decay begins in 1966 when 1:2 GeV=c momentum �? \\Gamma),% 0 5 10 15 20 25 30 [2] [4] [6] [8] [10] [12] Figure 1: The history of the j ! �? 0 flfl decay
(beta beta)_{0 nu}-decay: a possible test of the nuclear matrix element calculations
The existing calculations of the nuclear matrix elements of the neutrinoless double beta-decay differ by about a factor three. This uncertainty prevents quantative interpretation of the results of experiments searching for this process. We suggest here that the observation of the neutrinoless double beta-decay of several nuclei in future experiments of could allow to test different calculations of the nuclear matrix elements through the direct comparison of them with the experimental data.
S. M. Bilenky; J. A. Grifols
A Black Hole Conjecture and Rare Decays in Theories with Low Scale Gravity
In models with large extra dimensions, where the fundamental gravity scale can be in the electroweak range, gravitational effects in particle physics may be noticeable even at relatively low energies. In this paper, we perform simple estimates of the decays of elementary particles with a black hole intermediate state. Since black holes are believed to violate global symmetries, particle decays can violate lepton and baryon numbers. Whereas previous literature has claimed incompatibility between these rates (e.g. $p$-decay) and existing experimental bounds, we find suppressed baryon and lepton-violating rates due to a new conjecture about the nature of the virtual black holes. We assume here that black holes lighter than the (effective) Planck mass must have zero electric and color charge and zero angular momentum -- this statement is true in classical general relativity and we make the conjecture that it holds in quantum gravity as well. If true, the rates for proton-decay, neutron-antineutron oscillations, and lepton-violating rare decays are suppressed to below experimental bounds even for large extra dimensions with TeV-scale gravity. Neutron-antineutron oscillations and anomalous decays of muons, $\\tau$-leptons, and $K$ and $B$-mesons open a promising possibility to observe TeV gravity effects with a minor increase of existing experimental accuracy.
C. Bambi; A. D. Dolgov; K. Freese
Systematics of {alpha}-decay half-lives around shell closures
We present a systematic calculation of {alpha}-decay half-lives of even-even heavy and superheavy nuclei in the framework of the preformed {alpha} model. The microscopic {alpha}-daughter nuclear interaction potential is calculated by double-folding the density distributions of both {alpha} and daughter nuclei with a realistic effective Michigan three-Yukawa nucleon-nucleon interaction, and the microscopic Coulomb potential is calculated by folding the charge density distributions of the two interacting nuclei. The half-lives are found to be sensitive to the density dependence of the nucleon-nucleon interaction and the implementation of the Bohr-Sommerfeld quantization condition inherent in the Wentzel-Kramers-Brillouin approach. The {alpha}-decay half-lives obtained agree reasonably well with the available experimental data. Moreover, the study has been extended to the newly observed superheavy nuclei. The interplay of closed-shell effects in {alpha}-decay calculations is investigated. The {alpha}-decay calculations give the closed-shell effects of known spherical magicities, Z=82 and N=126, and further predict enhanced stabilities at N=152,162, and 184 for Z=100,108, and 114, owing to the stability of parent nuclei against {alpha} decays. It is worth noting that the aim of this work is not only to reproduce the experimental data better, but also to extend our understanding of {alpha}-decay half-lives around shell closures.
Ismail, M.; Ellithi, A. Y.; Botros, M. M.; Adel, A. [Physics Department, Faculty of Science, Cairo University (Egypt)
Structure effects in the region of superheavy elements via the $?$-decay chain of $^{293}$118
The $\\alpha$-decay chain of $^{293}$118, first proposed in the Berkeley cold fusion experiment $^{208}$Pb($^{86}$Kr,1n) and now retracted, is calculated by using the preformed cluster model (PCM) of one of us (RKG). Also, the possible branchings of $\\alpha$-particles to heavier cluster decays of all the parents in this chain are calculated for the first time. The calculated Q-values, penetrabilities and preformation factors for $\\alpha$-decays suggest that the $^{285}$114 nucleus with Z=114, N=171 is a magic nucleus, either due to the magicity of Z=114, or of N=172 or of both. The N=172 is proposed to be a magic number in certain relativistic mean-field calculations, but with Z=120. The calculated cluster decays point to new interesting possibilities of $^{14}$C decay of the $^{281}$112 parent, giving rise to a (reasonably) deformed Z=106, N=161, $^{267}$106 daughter (N=162 being now established as the deformed magic shell) or to a doubly magic $^{48}$Ca cluster emitted from any of the parent nucleus in the $\\alpha$-decay chain. Apparently, these are exciting new directions for future experiments.
Raj K. Gupta; Sushil Kumar; Rajesh Kumar; M. Balasubramaniam; W. Scheid
Neutron Interactions in the CUORE Neutrinoless Double Beta Decay Experiment
Neutrinoless double beta decay (0{nu}DBD) is a lepton-number violating process that can occur only for a massive Majorana neutrino. The search for 0{nu}DBD is currently the only practical experimental way to determine whether neutrinos are identical to their own antiparticles (Majorana neutrinos) or have distinct particle and anti-particle states (Dirac neutrinos). In addition, the observation of 0{nu}DBD can provide information about the absolute mass scale of the neutrino. The Cuoricino experiment was a sensitive search for 0{nu}DBD, as well as a proof of principle for the next generation experiment, CUORE. CUORE will search for 0{nu}DBD of {sup 130}Te with a ton-scale array of unenriched TeO{sub 2} bolometers. By increasing mass and decreasing the background for 0{nu}DBD, the half-life sensitivity of CUORE will be a factor of twenty better than that of Cuoricino. The site for both of these experiments is the Laboratori Nazionali del Gran Sasso, an underground laboratory with 3300 meters water equivalent rock overburden and a cosmic ray muon attenuation factor of 10{sup -6}. Because of the extreme low background requirements for CUORE, it is important that all potential sources of background in the 0{nu}DBD peak region at 2530 keV are well understood. One potential source of background for CUORE comes from neutrons, which can be produced underground both by ({alpha},n) reactions and by fast cosmic ray muon interactions. Preliminary simulations by the CUORE collaboration indicate that these backgrounds will be negligible for CUORE. However, in order to accurately simulate the expected neutron background, it is important to understand the cross sections for neutron interactions with detector materials. In order to help refine these simulations, I have measured the gamma-ray production cross sections for interactions of neutrons on the abundant stable isotopes of Te using the GEANIE detector array at the Los Alamos Neutron Science Center. In addition, I have used the GEANIE data to set an upper limit for the production of a 2529 keV gamma-ray from the {sup 126}Te(n,n{prime}{gamma}) reaction. This gamma-ray is a potential source of interference for the 0{nu}DBD peak. Based on this measurement, the contribution of this line to the background is expected to be negligible.
Dolinski, M J
Search for CP Violation in Charged-Xi and Lambda Hyperon Decays
We have compared the proton and antiproton angular distributions in 117 million Xi-minus -> Lambda + pi-minus -> proton + pi-minus + pi-minus and 41 million anti-Xi-minus -> anti-Lamba + pi-plus -> antiproton + pi-plus + pi-plus decays using a subset of the data from the HyperCP experiment (E871) at Fermilab. We find no evidence of CP violation, with the direct-CP-violating parameter $A_{\\Xi\\Lambda} = \\frac{\\alpha_{\\Xi}\\alpha_{\\Lambda} - \\bar{\\alpha}_{\\Xi}\\bar{\\alpha}_{\\Lambda}}{\\alpha_{\\Xi}\\alpha_{\\Lambda} + \\bar{\\alpha}_{\\Xi}\\bar{\\alpha}_{\\Lambda}} = [0.0+/-5.1(stat)+/-4.4(syst)]{\\times}10^{-4}$.
HyperCP Collaboration; T. Holmstrom; N. Leros; R. A. Burnstein; A. Chakravorty; A. Chan; Y. C. Chen; W. S. Choong; K. Clark; E. C. Dukes; C. Durandet; J. Felix; Y. Fu; G. Gidal; P. Gu; H. R. Gustafson; C. Ho; M. Huang; C. James; C. M. Jenkins; T. Jones; D. M. Kaplan; L. M. Lederman; M. J. Longo; F. Lopez; L. C. Lu; W. Luebke; K. B. Luk; K. S. Nelson; H. K. Park; J. P. Perroud; D. Rajaram; H. A. Rubin; P. K. Teng; J. Volk; C. G. White; S. L. White; P. Zyla
Experimental Investigation of Weak Non-Mesonic Decay of 10Be(Lambda)Hypernuclei at CEBAF
Hypernuclei are convenient laboratory to study the baryon-baryon weak interaction and associated effective Hamiltonian. The strangeness changing process, in which a Lambda hyperon converts to a neutron with a release up to 176 MeV, provides a clear signal for a conversion of an s-quark to a d-quark. We propose to perform a non-mesonic weak decay study of 10Be(Lambda)hypernuclei using the (e,eK) reaction. These investigations will fully utilize the unique parameters of the CEBAF CW electron beam and RF system and are enabled by (1) the use of new detector for alpha particles based on the recently developed RF timing technique with picosecond resolution and (2) the small angle and large acceptance kaon spectrometer-HKS in Hall C.
S. Majewski; L. Majling; A. Margaryan; L. Tang
The splitted laser beam filamentation in interaction of laser and an exponential decay inhomogeneous underdense plasma
The splitted beam filamentation in interaction of laser and an exponential decay inhomogeneous underdense plasma is investigated. Based on Wentzel-Kramers-Brillouin (WKB) approximation and paraxial/nonparaxial ray theory, simulation results show that the steady beam width and single beam filamentation along the propagation distance in paraxial case is due to the influence of ponderomotive nonlinearity. In nonparaxial case, the influence of the off-axial of {alpha}{sub 00} and {alpha}{sub 02} (the departure of the beam from the Gaussian nature) and S{sub 02} (the departure from the spherical nature) results in more complicated ponderomotive nonlinearity and changing of the channel density and refractive index, which led to the formation of two/three splitted beam filamentation and the self-distortion of beam width. In addition, influence of several parameters on two/three splitted beam filamentation is discussed.
Xia Xiongping; Yi Lin [Department of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Xu Bin [Department of Mathematics and Information Sciences, North China Institute of Water Conservancy and Hydroelectric Power, Zhengzhou 450011 (China); Lu Jianduo [Department of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081 (China)
Gamma-ray decay schemes for $sup 93$Kr, $sup 93$Rb, and $sup 93$Sr
A study of the gamma-ray de-excitation following the beta decays of $sup 93$Kr, $sup 93$Rb, and $sup 93$Sr using the TRISTAN on-line separator facility is reported. Gamma-ray singles and gamma-gamma coincidence measurements were made using Ge(Li) detectors. Of the 162 gamma rays observed in the decay of $sup 93$Sr, 143, representing more than 99 percent of the total gamma-ray intensity observed, were placed in a level scheme containing 36 levels. For the decay of $sup 93$Rb, 243 gamma rays were observed, of which 231 are placed in a level scheme consisting of 74 levels. This again represents a placement of over 99 percent of the total gamma-ray intensity measured. In the case of the $sup 93$Kr decay approximately 98.5 percent of the observed gamma-ray intensity has been accounted for by the proposed level scheme. This results from the placement of 203 of the 217 gamma rays assigned to this decay in a level scheme comprising 56 levels. Beta-branching for these decays were determined from transition intensity balances. Spin and parity assignments were proposed, whenever possible, on the basis of gamma-ray transition probabilities and deduced log ft values. A comparison is made with the available reaction data for the $sup 93$Y level scheme. In all cases an attempt has been made to explain some of the levels in terms of the nuclear shell model and decay systematics. 18 figures, 20 tables, 68 references. (auth)
Bischof, C.J.
Parameters of Cascade Gamma-Decay of Compound-Nuclei Nd-146, Gd-156, Yb-172, Ta-182, W-184, Os-191, Th-231,233, U-239, Pu-240 from Experimental Data of Reaction $(n,?)$
Re-analysis of experimental data on primary gamma-transitions averaged over some energy intervals of neutron resonances has been performed. Approximation of their cumulative sums together with extrapolation of the obtained distribution to zero value allowed us to determine mean intensities of of E1- and M1-transitions, their probable number and total dispersion of intensity deviations from the mean value. The level density and sum of radiative strength functions determined in this way confirm main peculiarities of these nuclear parameters determined from intensities of the two-step gamma-cascades.
A. M. Sukhovoj; V. A. Khitrov
Semileptonic B to D Decays at Nonzero Recoil with 2+1 Flavors of Improved Staggered Quarks
The Fermilab Lattice-MILC collaboration is completing a comprehensive program of heavy-light physics on the MILC (2+1)-flavor asqtad ensembles with lattice spacings as small as 0.045 fm and light-to-strange-quark mass ratios as low as 1/20. We use the Fermilab interpretation of the clover action for heavy valence quarks and the asqtad action for light valence quarks. The central goal of the program is to provide ever more exacting tests of the unitarity of the CKM matrix. We give a progress report on one part of the program, namely the analysis of the semileptonic decay B to D at both zero and nonzero recoil. Although final results are not presented, we discuss improvements in the analysis methods, the statistical errors, and the parameter coverage that we expect will lead to a significant reduction in the final error for |V{sub cb}| from this decay channel.
Qiu, Si-Wei; /Utah U.; DeTar, Carleton; /Utah U.; Du, Daping; /Iowa U.; Kronfeld, Andreas S.; /Fermilab; Laiho, Jack; /Strathclyde U. /Glasgow U.; Van de Water, Ruth S.; /Brookhaven
Search for CP Violation using $T$-odd Correlations in $D^0 \\to K^+ K^- \\pi^+ \\pi^-$ Decays
We search for CP violation in a sample of 4.7 x 10{sup 4} Cabibbo suppressed D{sup 0} {yields} K{sup +}K{sup -}{pi}{sup +}{pi}{sup -} decays. We use 470 fb{sup -1} of data recorded by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} storage rings running at center-of-mass energies near 10.6 GeV. CP violation is searched for in the difference between the T-odd asymmetries, obtained using triple product correlations, measured for D{sup 0} and {bar D}{sup 0} decays. The measured CP violation parameter is A{sub T} = (1.0 {+-} 5.1{sub stat} {+-} 4.4{sub syst}) x 10{sup -3}.
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Battaglia, M.; Brown, D.N.; Hooberman, B.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; Tanabe, T.; /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Wisconsin U., Madison
Effect of room air recirculation delay on the decay rate of tracer gas Effect of room air recirculation delay on the decay rate of tracer gas concentration Title Effect of room air recirculation delay on the decay rate of tracer gas concentration Publication Type Journal Article Year of Publication 2007 Authors Lorenzetti, David M., Astrid H. Kristoffersen, and Ashok J. Gadgil Journal Indoor Air Pagination 7 Keywords recirculating ventilation, tracer decay rate Abstract Tracer gas measurements are used to estimate the flow rate of fresh air into a room or building. These methods commonly account for the decay of tracer gas concentration as the result of ventilation air supply and infiltration, using a well-mixed model of the space. Some researchers also have considered the effect of leakage in the ventilation ductwork. This paper considers the effect of recirculation through ventilation ducts on the calculated fresh air supply rate. Transport delay in the ducts can significantly alter the time evolution of tracer concentration, and hence alter the estimated air change rate.
Massive black hole pairs in clumpy, self-gravitating circumnuclear disks: stochastic orbital decay
We study the dynamics of massive black hole pairs in clumpy gaseous circumnuclear disks. We track the orbital decay of the light, secondary black hole M_{\\bullet2} orbiting around the more massive primary at the center of the disk, using N-body/SPH simulations. We find that the gravitational interaction of M_{\\bullet2} with massive clumps M_cl erratically perturbs the otherwise smooth orbital decay. In close encounters with massive clumps, gravitational slingshots can kick the secondary black hole out of the disk plane. The black hole moving on an inclined orbit then experiences the weaker dynamical friction of the stellar background, resulting in a longer orbital decay timescale. Interactions between clumps can also favor orbital decay when the black hole is captured by a massive clump which is segregating toward the center of the disk. The stochastic behavior of the black hole orbit emerges mainly when the ratio M_{\\bullet2}/M_cl falls below unity, with decay timescales ranging from ~1 to ~50 Myr. This sugg...
Colpi, Monica
Fission decay of N = Z nuclei at high angular momentum: $^{60}$Zn
Using a unique two-arm detector system for heavy ions (the BRS, binary reaction spectrometer) coincident fission events have been measured from the decay of $^{60}$Zn compound nuclei formed at 88MeV excitation energy in the reactions with $^{36}$Ar beams on a $^{24}$Mg target at $E_{lab}(^{36}$Ar) = 195 MeV. The detectors consisted of two large area position sensitive (x,y) gas telescopes with Bragg-ionization chambers. From the binary coincidences in the two detectors inclusive and exclusive cross sections for fission channels with differing losses of charge were obtained. Narrow out-of-plane correlations corresponding to coplanar decay are observed for two fragments emitted in binary events, and in the data for ternary decay with missing charges from 4 up to 8. After subtraction of broad components these narrow correlations are interpreted as a ternary fission process at high angular momentum through an elongated shape. The lighter mass in the neck region consists dominantly of two or three-particles. Differential cross sections for the different mass splits for binary and ternary fission are presented. The relative yields of the binary and ternary events are explained using the statistical model based on the extended Hauser-Feshbach formalism for compound nucleus decay. The ternary fission process can be described by the decay of hyper-deformed states with angular momentum around 45-52 $hbar$.
W. Von Oertzen; V. Zherebchevsky; B. Gebauer; C. Schulz; S. Thummerer; D. Kamanin; G. Royer; T. Wilpert
Effective Yukawa couplings and flavor-changing Higgs boson decays at linear colliders
We analyze the advantages of a linear-collider program for testing a recent theoretical proposal where the Higgs boson Yukawa couplings are radiatively generated, keeping unchanged the standard-model mechanism for electroweak-gauge-symmetry breaking. Fermion masses arise at a large energy scale through an unknown mechanism, and the standard model at the electroweak scale is regarded as an effective field theory. In this scenario, Higgs boson decays into photons and electroweak gauge-boson pairs are considerably enhanced for a light Higgs boson, which makes a signal observation at the LHC straightforward. On the other hand, the clean environment of a linear collider is required to directly probe the radiative fermionic sector of the Higgs boson couplings. Also, we show that the flavor-changing Higgs boson decays are dramatically enhanced with respect to the standard model. In particular, we find a measurable branching ratio in the range (10{sup -4}-10{sup -3}) for the decay H{yields}bs for a Higgs boson lighter than 140 GeV, depending on the high-energy scale where Yukawa couplings vanish. We present a detailed analysis of the Higgs boson production cross sections at linear colliders for interesting decay signatures, as well as branching-ratio correlations for different flavor-conserving/nonconserving fermionic decays.
Gabrielli, E. [CERN, PH-TH, CH-1211 Geneva 23 (Switzerland); Mele, B. [INFN, Sezione di Roma, c/o Dipartimento di Fisica, Universita di Roma 'La Sapienza', Piazzale A. Moro 2, I-00185 Rome (Italy)
Finite width effects in Higgs boson decays as a means of measuring massive particle widths
We calculate decays of a standard model Higgs boson via a virtual massive particle and discuss how this depends on the massive particle total width. If the partial width for a Higgs boson to decay via a virtual massive particle can be measured, this gives a measurement of that massive particle{close_quote}s width. We discuss how one would go about measuring these partial widths of a Higgs boson experimentally, and how this could lead to a measurement of the {ital W} boson and {ital t} quark widths. For the latter, extreme dependence on the Higgs boson mass and the small {ital H}{r_arrow}{ital tt{sup {asterisk}}} branching ratios mean that little can be learned about the {ital t} quark width. For the former there is also a larger dependence on the Higgs boson mass; however, this can be removed by taking the ratio of {ital H}{r_arrow}{ital WW{sup {asterisk}}} decays to {ital H}{r_arrow}{ital ZZ{sup {asterisk}}} decays. This ratio also has the advantage of being fairly insensitive to physics beyond the standard model. Unfortunately, for Higgs boson masses of interest the {ital H}{r_arrow}{ital ZZ{sup {asterisk}}} branching ratio is small enough that we require many thousands of tagged Higgs boson decays before an accurate measurement of the {ital W} width can be made. This is likely to be hard experimentally. {copyright} {ital 1996 The American Physical Society.}
Summers, D.J. [Department of Physics, University of Wisconsin--Madison, 1150 University Avenue, Madison, Wisconsin 53706 (United States)
Radiative decays of the psi(3097) to two meson final states
The MARK III detector operating at the SPEAR storage ring has acquired a sample of 2.7 x 10/sup 6/ produced psi(3097)'s. These events are used to investigate the radiative decays of the psi to two meson final states. Such decays are of topical interest because of the unusual QCD laboratory they provide - of particular interest is the possibility of observing glueball states. The process psi ..-->.. ..gamma pi../sup +/..pi../sup -/ is studied. The f(1270) tensor meson is observed and the helicity structure of its production is measured. The data indicate that helicity 2 is suppressed, in disagreement with lowest order QCD calculations. Evidence is presented for the first observation of the theta(1700) in the ..pi../sup +/..pi../sup -/ final state. The strong, but not complete, suppression of this state in the ..pi pi.. channel, combined with the absence of a J/sup P/ = 2/sup +/ signal in a recent MARK III analysis of psi ..-->.. ..gamma.. rho rho, suggest a very mysterious nature for the theta(1700). The process psi ..-->.. ..gamma..K/sup +/K/sup -/ is also studied. The f'(1515) tensor meson is observed with a branching ratio in agreement with the SU(3) symmetry prediction for the standard two gluon radiative decay diagram with no mixing corrections. The helicity structure of the f'(1515) is measured for the first time, and is found to be similar to that of the f(1270). The theta(1700) is observed with high statistics. Its spin and parity are measured, with the result that J/sup P/ = 2/sup +/ is preferred over J/sup P/ = 0/sup +/ at the 99.9% C.L. In addition, evidence is presented for a remarkable narrow state, designated the xi(2220). Its parameters are measured to be: m = 2.218 +- 0.003 +- 0.010 GeV, GAMMA less than or equal to 0.040 GeV at 95% C.L., and BR(psi ..-->.. ..gamma..xi(2220))BR(xi(2220) ..-->.. K/sup +/K/sup -/) = (5.7 +- 1.9 +- 1.4) x 10/sup -5/.
Einsweiler, K.F.
Super-allowed beta-decay rates in 1d5/2 shell in Coriolis coupling model
The expression for super-allowed beta-decay transition rates have been derived within the context of Coriolis coupling model. The derived expressions, valid for the beta-decay between any two mirror nuclei, has been applied to calculate super-allowed beta-decay transition rates of 21Na, 21Mg, 21Al, and 21Si. The calculated rates agree well with the data and the calculations done using the shell model with configuration admixture.
M. Sultan Parvez; F. Bary Malik
Depth Requirements for a Tonne-scale 76Ge Neutrinoless Double-beta Decay Experiment
Neutrinoless double-beta decay experiments can potentially determine the Majorana or Dirac nature of the neutrino, and aid in understanding the neutrino absolute mass scale and hierarchy. Future 76Ge-based searches target a half-life sensitivity of >10^27 y to explore the inverted neutrino mass hierarchy. Reaching this sensitivity will require a background rate of required to reach this background goal in a tonne-scale experiment with a compact (copper and lead) shield based on Monte Carlo calculations of cosmic-ray background rates. We find that, in light of the presently large uncertainties in these types of calculations, a site with an underground depth >~5200 mwe is required for a tonne-scale experiment with a compact shield similar to the planned 40-kg MAJORANA DEMONSTRATOR. The required overburden is highly dependent on the chosen shielding configuration and could be relaxed significantly if, for example, a liquid cryogen and water shield, or an active neutron shield were employed. Operation of the MAJORANA DEMONSTRATOR and GERDA detectors will serve to reduce the uncertainties on cosmic-ray background rates and will impact the choice of shielding style and location for a future tonne-scale experiment. 4/2013: The peer review process revealed that one of the veto rejection factors (the factor-of-4 described on p12) needs to be better established. Our reevaluation of this parameter to date has not yielded strong support for the value stated in the manuscript, and we require further study to develop a solid estimate. This further study will supersede the work described in this manuscript, and may or may not lead to the same conclusion regarding the ~>5200 mwe requirement for future tonne-scale 76Ge neutrinoless double beta decay experiments.
The MAJORANA Collaboration; E. Aguayo; F. T. Avignone III; H. O. Back; A. S. Barabash; M. Bergevin; F. E. Bertrand; M. Boswell; V. Brudanin; M. Busch; Y-D. Chan; C. D. Christofferson; J. I. Collar; D. C. Combs; R. J. Cooper; J. A. Detwiler; P. J. Doe; Yu. Efremenko; V. Egorov; H. Ejiri; S. R. Elliott; J. Esterline; J. E. Fast; N. Fields; P. Finnerty; F. M. Fraenkle; V. M. Gehman; G. K. Giovanetti; M. P. Green; V. E. Guiseppe; K. Gusey; A. L. Hallin; R. Hazama; R. Henning; A. Hime; E. W. Hoppe; M. Horton; S. Howard; M. A. Howe; R. A. Johnson; K. J. Keeter; M. E. Keillor; C. Keller; J. D. Kephart; M. F. Kidd; A. Knecht; O. Kochetov; S. I. Konovalov; R. T. Kouzes; B. D. LaFerriere; B. H. LaRoque; J. Leon; L. E. Leviner; J. C. Loach; S. MacMullin; M. G. Marino; R. D. Martin; D. -M. Mei; J. H. Merriman; M. L. Miller; L. Mizouni; M. Nomachi; J. L. Orrell; N. R. Overman; D. G. Phillips II; A. W. P. Poon; G. Perumpilly; G. Prior; D. C. Radford; K. Rielage; R. G. H. Robertson; M. C. Ronquest; A. G. Schubert; T. Shima; M. Shirchenko; K. J. Snavely; V. Sobolev; D. Steele; J. Strain; K. Thomas; V. Timkin; W. Tornow; I. Vanyushin; R. L. Varner; K. Vetter; K. Vorren; J. F. Wilkerson; B. A. Wolfe; E. Yakushev; A. R. Young; C. -H. Yu; V. Yumatov; C. Zhang
Shell model formalism for all hypernuclei types: A guide to solving the nonmesonic weak decay puzzle
We extend to odd-odd core hypernuclei our independent particle shell model (IPSM) formalism developed previously for the evaluation of the {gamma}{sub NM},{gamma}{sub n/p}, and a{sub {lambda}} hypernuclear weak decay observables. The present procedure reproduces the even-odd and even-even core results as particular cases. Adopting the standard strangeness-changing weak {lambda}N{yields}NN transition potential with exchange of the complete pseudoscalar and vector meson octets ({pi},{eta},K,{rho},{omega},K*) we get simple analytical expressions for all observables. Numerical values for {sub {lambda}}{sup 4}He,{sub {lambda}}{sup 5}He, {sub {lambda}}{sup 11}B,{sub {lambda}}{sup 12}C,{sub {lambda}}{sup 16}O, {sub {lambda}}{sup 17}O, and {sub {lambda}}{sup 28}Si hypernuclei are obtained and compared with available experimental data, putting special attention on the asymmetry parameter. We remark that, in the present form, the IPSM gives roughly the same value of a{sub {lambda}} for all hypernuclei in contradiction with experiments. We stress the necessity of introducing configuration mixing to go beyond the IPSM taking into account, in a more realistic way, nuclear structure effects. Moreover, one could to include more relevant degrees of freedom, even within the IPSM framework, like: (i) modifications of the exchange potential (two-pion, a{sub 1} meson, {delta}T=3/2 terms of vector mesons, etc.), (ii) final state interactions accounting for the distortion of the plane waves of emitted nucleons, and (iii) two-nucleon induced decay, as possible ways to solve the puzzle.
Barbero, C.; Mariano, A.; Samana, A. [Departamento de Fisica, Universidad Nacional de La Plata, C. C. 67, 1900 La Plata (Argentina) and Instituto de Fisica CCT La Plata, CONICET, 1900 La Plata (Argentina); Department of Physics, Texas A and M University-Commerce, P. O. Box 3011, Commerce, Texas (United States)
Study on the radiative decays of $?(nS)\\to ?_b+?$
In this work, we investigate the characteristics of the spin-singlet state $\\eta_b$ of the bottomonia family via the radiative decays of $\\Upsilon(nS)\\to \\eta_b+\\gamma$. The theoretical estimation of the decay widths is carried out in terms of the light-front quark model (LFQM). Recently CLEO and BaBar collaborations have measured $\\mathcal{B}(\\Upsilon(3S)\\to\\gamma\\eta_b)$ and the mass of ${\\eta_b}$. In terms of the data we fix the concerned input parameters in our calculations of $\\Upsilon(nS)\\to \\eta_b+\\gamma$. A special attention is paid on the transition of $\\Upsilon(5S)\\to \\eta_b+\\gamma$. The BELLE data showed that the width of $\\Upsilon(5S)\\to \\Upsilon(2S,1S)+\\pi\\pi$ is two orders larger than that of $\\Upsilon(4S)\\to \\Upsilon(2S,1S)+\\pi\\pi$, thus some theoretical explanations have been proposed. Among them, it is suggested the inelastic final state interaction (IFSI) $\\Upsilon(5S)\\to B\\bar B\\to \\Upsilon(1S)+\\pi\\pi$ may be a natural one. If so, a similar mechanism also applies to $\\Upsilon(5S)\\to B^{(*)}\\bar B^{(*)}\\to \\eta_b+\\gamma$, the precise measurement would serve as a good test whether $\\Upsilon(5S)$ possess exotic components. Our calculation in the LFQM indicates that the rate of the direct process $\\Upsilon(5S)\\to\\eta_b+\\gamma$ is not anomalous compared to $\\Upsilon(mS)\\to\\eta_b+\\gamma (m=1,2,3,4)$, thus if the IFSI does apply, the rate of $\\Upsilon(5S)\\to\\eta_b+\\gamma$ should be larger than the others by orders.
Hong-Wei Ke; Xue-Qian Li; Xiang Liu
A Search for a Light Charged Higgs Boson Decaying to cs at ?s = 7 TeV.
??A search for a light charged Higgs boson decaying into cs is presented using data recorded in pp collisions at ?s = 7 TeV. The� (more)
Martyniuk, Alex Christopher
First Direct Double- Decay Q-Value Measurement of 82Se in Support of Understanding the Nature of the Neutrino
In anticipation of results from current and future double- decay studies, we report a measurement resulting in a 82Se double- decay Q value of 2997.9(3) keV, an order of magnitude more precise than the currently accepted value. We also present preliminary results of a calculation of the 82Se neutrinoless double- decay nuclear matrix element that corrects in part for the small size of the shell model single-particle space. The results of this work are important for designing next generation double- decay experiments and for the theoretical interpretations of their observations.
Lincoln, David L. [NSCL, Michigan State University, East Lansing; Holt, Jason D. [Technische Univ. Darmstadt/GSI/UTK/ORNL; Bollen, Georg [NSCL, Michigan State University, East Lansing; Brodeur, Maxime [NSCL, Michigan State University, East Lansing; Bustabad, Scott [NSCL, Michigan State University, East Lansing; Engel, Jonathan [University of North Carolina, Chapel Hill; Novario, Samuel J. [NSCL, Michigan State University, East Lansing; Redshaw, Matthew [NSCL, Michigan State Univ.,/Central Michigan Univ.-Mt. Pleasant; Ringle, Ryan [NSCL, Michigan State University, East Lansing; Schwarz, Stefan [NSCL, Michigan State University, East Lansing
Using NERSC Systems, Physcists Close in on a Rare-Particle Decay Process
Using NERSC Systems, Using NERSC Systems, Physcists Close in on a Rare-Particle Decay Process Using NERSC Systems, Physicists Close In on a Rare-Particle Decay Process Underground Experiment May Unlock the Mysteries of the Neutrino June 11, 2012 | Tags: Accelerator Science, High Energy Physics (HEP), Hopper NERSC Contact: Linda Vu, email@example.com, +1 510 495 2402 exo-1.jpg Located at the Waste Isolation Pilot Plant near Carlsbad, New Mexico, EXO-200 is a 200-kg detector using liquid xenon, enriched in the isotope 136, to detect "neutrino-less double beta decay." With help from supercomputers at the Department of Energy's National Energy Research Scientific Computing Center (NERSC), the Enriched Xenon Observatory experiment (EXO-200) has placed the most stringent constraints
Elevated Nitrogen Slows Carbon Decay in Forest Soils | U.S. DOE Office of
Elevated Nitrogen Slows Carbon Decay in Forest Soils Elevated Nitrogen Slows Carbon Decay in Forest Soils Biological and Environmental Research (BER) BER Home About Research Facilities Science Highlights Searchable Archive of BER Highlights External link Benefits of BER Funding Opportunities Biological & Environmental Research Advisory Committee (BERAC) News & Resources Contact Information Biological and Environmental Research U.S. Department of Energy SC-23/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-3251 F: (301) 903-5051 E: email@example.com More Information » February 2013 Elevated Nitrogen Slows Carbon Decay in Forest Soils New clues emerge about microbial decomposition mechanisms. Print Text Size: A A A Subscribe FeedbackShare Page Click to enlarge photo. Enlarge Photo
Observation of ?_{cJ} decaying into the p\\bar{p}K^{+}K^{-} final state
First measurements of the decays of the three $\\chi_{cJ}$ states to $p\\bar{p}K^{+}K^{-}$ final states are presented. Intermediate $\\phi\\to K^{+}K^{-}$ and $\\Lambda(1520)\\to pK^{-}$ resonance states are observed, and branching fractions for $\\chi_{cJ}\\to \\bar{p}K^{+}\\Lambda(1520)$, $\\Lambda(1520) \\bar{\\Lambda}(1520)$, and $\\phi p\\bar{p}$ are reported. We also measure branching fractions for direct $\\chi_{cJ}\\to p\\bar{p} K^{+}K^{-}$ decays. These are first observations of $\\chi_{cJ}$ decays to unstable baryon resonances and provide useful information about the $\\chi_{cJ}$ states. The experiment uses samples of $\\chi_{cJ}$ mesons produced via radiative transitions from 106 million $\\psi^{\\prime}$ mesons collected in the BESIII detector at the BEPCII $e^+e^-$ collider.
BESIII Collaboration
Search for CP Violation in the Decay $D^+\\rightarrow K^0_S K^+$
We search for CP violation in the decay $D^+\\rightarrow K^0_S K^+$ using a data sample with an integrated luminosity of 977 fb$^{-1}$ collected with the Belle detector at the KEKB $e^+e^-$ asymmetric-energy collider. No CP violation has been observed and the CP asymmetry in $D^+\\rightarrow K^0_S K^+$ decay is measured to be $(-0.25\\pm0.28\\pm0.14)%$, which is the most sensitive measurement to date. After subtracting CP violation due to $K^0-\\bar{K}^0$ mixing, the CP asymmetry in $D^+\\rightarrow\\bar{K}^0 K^+$ decay is found to be $(+0.08\\pm0.28\\pm0.14)%$.
B. R. Ko; E. Won; I. Adachi; H. Aihara; K. Arinstein; D. M. Asner; T. Aushev; A. M. Bakich; K. Belous; V. Bhardwaj; B. Bhuyan; A. Bondar; G. Bonvicini; A. Bozek; M. Bra?ko; T. E. Browder; V. Chekelian; A. Chen; P. Chen; B. G. Cheon; K. Chilikin; R. Chistov; K. Cho; S. -K. Choi; Y. Choi; D. Cinabro; J. Dalseno; Z. Dole�al; D. Dutta; S. Eidelman; S. Esen; H. Farhat; J. E. Fast; V. Gaur; N. Gabyshev; S. Ganguly; R. Gillard; Y. M. Goh; B. Golob; K. Hayasaka; H. Hayashii; Y. Hoshi; W. -S. Hou; H. J. Hyun; T. Iijima; A. Ishikawa; Y. Iwasaki; T. Julius; J. H. Kang; E. Kato; C. Kiesling; H. O. Kim; J. B. Kim; K. T. Kim; M. J. Kim; Y. J. Kim; K. Kinoshita; J. Klucar; S. Korpar; R. T. Kouzes; P. Kri�an; P. Krokovny; T. Kuhr; T. Kumita; A. Kuzmin; Y. -J. Kwon; Y. Li; C. Liu; D. Liventsev; R. Louvot; K. Miyabayashi; H. Miyata; R. Mizuk; G. B. Mohanty; A. Moll; N. Muramatsu; Y. Nagasaka; E. Nakano; M. Nakao; E. Nedelkovska; C. Ng; N. Nellikunnummel; S. Nishida; K. Nishimura; O. Nitoh; S. Ogawa; T. Ohshima; S. Okuno; C. Oswald; P. Pakhlov; G. Pakhlova; H. Park; H. K. Park; T. K. Pedlar; R. Pestotnik; M. Petri?; L. E. Piilonen; K. Prothmann; M. Ritter; M. R�hrken; H. Sahoo; T. Saito; Y. Sakai; S. Sandilya; L. Santelj; T. Sanuki; Y. Sato; O. Schneider; G. Schnell; C. Schwanda; A. J. Schwartz; K. Senyo; O. Seon; M. E. Sevior; M. Shapkin; C. P. Shen; T. -A. Shibata; J. -G. Shiu; A. Sibidanov; F. Simon; P. Smerkol; Y. -S. Sohn; E. Solovieva; M. Stari?; T. Sumiyoshi; G. Tatishvili; Y. Teramoto; K. Trabelsi; T. Tsuboyama; M. Uchida; T. Uglov; Y. Unno; S. Uno; C. Van Hulse; P. Vanhoefer; G. Varner; C. H. Wang; M. -Z. Wang; P. Wang; Y. Watanabe; K. M. Williams; Y. Yamashita; C. C. Zhang; V. Zhilich; A. Zupanc
A Global Model of $\\beta^-$-Decay Half-Lives Using Neural Networks
Statistical modeling of nuclear data using artificial neural networks (ANNs) and, more recently, support vector machines (SVMs), is providing novel approaches to systematics that are complementary to phenomenological and semi-microscopic theories. We present a global model of $\\beta^-$-decay halflives of the class of nuclei that decay 100% by $\\beta^-$ mode in their ground states. A fully-connected multilayered feed forward network has been trained using the Levenberg-Marquardt algorithm, Bayesian regularization, and cross-validation. The halflife estimates generated by the model are discussed and compared with the available experimental data, with previous results obtained with neural networks, and with estimates coming from traditional global nuclear models. Predictions of the new neural-network model are given for nuclei far from stability, with particular attention to those involved in r-process nucleosynthesis. This study demonstrates that in the framework of the $\\beta^-$-decay problem considered here, ...
Costiris, N; Gernoth, K A; Mavrommatis, E
Indoor Radon and Its Decay Products: Concentrations, Causes, and Control Strategies
This report is an introduction to the behavior of radon 222 and its decay products in indoor air. This includes review of basic characteristics of radon and its decay products and of features of the indoor environment itself, all of which factors affect behavior in indoor air. The experimental and theoretical evidence on behavior of radon and its decay products is examined, providing a basis for understanding the influence of geological, structural, and meteorological factors on indoor concentrations, as well as the effectiveness of control techniques. We go on to examine three important issues concerning indoor radon. We thus include (1) an appraisal of the concentration distribution in homes, (2) an examination of the utility and limitations of popular monitoring techniques and protocols, and (3) an assessment of the key elements of strategies for controlling radon levels in homes.
Towards a global fit to extract the B->Xs gamma decay rate and Vub
The total B->Xs gamma decay rate and the CKM-matrix element Vub play an important role in finding indirect evidence for new physics affecting the flavor sector of the Standard Model, complementary to direct searches at the LHC and Tevatron. Their determination from inclusive B-meson decays requires the precise knowledge of the parton distribution function of the b quark in the B meson, called the shape function. We implement a new model-independent framework for the shape function with reliable uncertainties based on an expansion in a suitable set of basis functions. We present the current status of a global fit to BaBar and Belle data to extract the shape function and the B->Xs gamma decay rate.
Florian U. Bernlochner; Heiko Lacker; Zoltan Ligeti; Iain W. Stewart; Frank J. Tackmann; Kerstin Tackmann
Magnetars: Time Evolution, Superfluid Properties, and Mechanism of Magnetic Field Decay
We calculate the coupled thermal evolution and magnetic field decay in relativistic model neutron stars threaded by superstrong magnetic fields (B > 10^{15} G). Our main goal is to evaluate how such ``magnetars'' evolve with time and how field decay modifies the transitions to core superfluidity and cooling dominated by surface X-ray emission. Observations of a thermal X-ray spectral component and fast timing noise place strong constraints on the presence of a superfluid core. We find that the transition to core superfluidity can be significantly delayed by field decay in the age range ~ 10^3-10^5 yrs. The mechanism of Hall drift is related to the stability of the core magnetic field, and to currents flowing outward through the crust. The heating effect is enhanced if it is continuous rather than spasmodic. Condensation of a heavy element layer at the surface is shown to cause only modest changes in the outward conduction of heat.
P. Arras; A. Cumming; C. Thompson
The NEXT experiment: A high pressure xenon gas TPC for neutrinoless double beta decay searches
Neutrinoless double beta decay is a hypothetical, very slow nuclear transition in which two neutrons undergo beta decay simultaneously and without the emission of neutrinos. The importance of this process goes beyond its intrinsic interest: an unambiguous observation would establish a Majorana nature for the neutrino and prove the violation of lepton number. NEXT is a new experiment to search for neutrinoless double beta decay using a radiopure high-pressure xenon gas TPC, filled with 100 kg of Xe enriched in Xe-136. NEXT will be the first large high-pressure gas TPC to use electroluminescence readout with SOFT (Separated, Optimized FuncTions) technology. The design consists in asymmetric TPC, with photomultipliers behind a transparent cathode and position-sensitive light pixels behind the anode. The experiment is approved to start data taking at the Laboratorio Subterr\\'aneo de Canfranc (LSC), Spain, in 2014.
D. Lorca; J. Mart�n-Albo; F. Monrabal; for the NEXT Collaboration
Detection of the Characteristic Pion-Decay Signature in Supernova Remnants
Cosmic rays are particles (mostly protons) accelerated to relativistic speeds. Despite wide agreement that supernova remnants (SNRs) are the sources of galactic cosmic rays, unequivocal evidence for the acceleration of protons in these objects is still lacking. When accelerated protons encounter interstellar material, they produce neutral pions, which in turn decay into gamma rays. This offers a compelling way to detect the acceleration sites of protons. The identification of pion-decay gamma rays has been difficult because high-energy electrons also produce gamma rays via bremsstrahlung and inverse Compton scattering. We detected the characteristic pion-decay feature in the gamma-ray spectra of two SNRs, IC 443 and W44, with the Fermi Large Area Telescope. This detection provides direct evidence that cosmic-ray protons are accelerated in SNRs.
:,; Ajello, M; Allafort, A; Baldini, L; Ballet, J; Barbiellini, G; Baring, M G; Bastieri, D; Bechtol, K; Bellazzini, R; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A W; Bottacini, E; Brandt, T J; Bregeon, J; Brigida, M; Bruel, P; Buehler, R; Busetto, G; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cecchi, C; �elik, �; Charles, E; Chaty, S; Chaves, R C G; Chekhtman, A; Cheung, C C; Chiang, J; Chiaro, G; Cillis, A N; Ciprini, S; Claus, R; Cohen-Tanugi, J; Cominsky, L R; Conrad, J; Corbel, S; Cutini, S; D'Ammando, F; de Angelis, A; de Palma, F; Dermer, C D; Silva, E do Couto e; Drell, P S; Drlica-Wagner, A; Falletti, L; Favuzzi, C; Ferrara, E C; Franckowiak, A; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Germani, S; Giglietto, N; Giommi, P; Giordano, F; Giroletti, M; Glanzman, T; Godfrey, G; Grenier, I A; Grondin, M -H; Grove, J E; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hayashi, K; Hays, E; Hewitt, J; Hill, A B; Hughes, R E; Jackson, M S; Jogler, T; J�hannesson, G; Johnson, A S; Kamae, T; Kataoka, J; Katsuta, J; Kn�dlseder, J; Kuss, M; Lande, J; Larsson, S; Latronico, L; Lemoine-Goumard, M; Longo, F; Loparco, F; Lovellette, M N; Lubrano, P; Madejski, G M; Massaro, F; Mayer, M; Mazziotta, M N; McEnery, J E; Mehault, J; Michelson, P F; Mignani, R P; Mitthumsiri, W; Mizuno, T; Moiseev, A A; Monzani, M E; Morselli, A; Moskalenko, I V; Murgia, S; Nakamori, T; Nemmen, R; Nuss, E; Ohno, M; Ohsugi, T; Omodei, N; Orienti, M; Orlando, E; Ormes, J F; Paneque, D; Perkins, J S; Pesce-Rollins, M; Piron, F; Pivato, G; Rain�, S; Rando, R; Razzano, M; Razzaque, S; Reimer, A; Reimer, O; Ritz, S; Romoli, C; S�nchez-Conde, M; Schulz, A; Sgr�, C; Simeon, P E; Siskind, E J; Smith, D A; Spandre, G; Spinelli, P; Stecker, F W; Strong, A W; Suson, D J; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, J G; Thayer, J B; Thompson, D J; Thorsett, S E; Tibaldo, L; Tibolla, O; Tinivella, M; Troja, E; Uchiyama, Y; Usher, T L; Vandenbroucke, J; Vasileiou, V; Vianello, G; Vitale, V; Waite, A P; Werner, M; Winer, B L; Wood, K S; Wood, M; Yamazaki, R; Yang, Z; Zimmer, S
An experimental investigation of double beta decay of /sup 100/Mo
New limits on half-lives for several double beta decay modes of /sup 100/Mo were obtained with a novel experimental system which included thin source films interleaved with a coaxial array of windowless silicon detectors. Segmentation and timing information allowed backgrounds originating in the films to be studied in some detail. Dummy films containing /sup 96/Mo were used to assess remaining backgrounds. With 0.1 mole years of /sup 100/Mo data collected, the lower half-life limits at 90% confidence were 2.7 /times/ 10/sup 18/ years for decay via the two-neutrino mode, 5.2 /times/10/sup 19/ years for decay with the emission of a Majoron, and 1.6 /times/ 10/sup 20/ years and 2.2 /times/ 10/sup 21/ years for neutrinoless 0/sup +/ ..-->.. 2/sup +/ and 0/sup +/ ..-->.. 0/sup +/ transitions, respectively. 50 refs., 38 figs., 11 tabs.
Dougherty, B.L.
Improved Limits on $B^{0}$ Decays to Invisible $(+gamma)$ Final States
We establish improved upper limits on branching fractions for B{sup 0} decays to final states where the decay products are purely invisible (i.e., no observable final state particles) and for final states where the only visible product is a photon. Within the Standard Model, these decays have branching fractions that are below the current experimental sensitivity, but various models of physics beyond the Standard Model predict significant contributions for these channels. Using 471 million B{bar B} pairs collected at the {Upsilon} (4S) resonance by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage ring at the SLAC National Accelerator Laboratory, we establish upper limits at the 90% confidence level of 2.4 x 10{sup -5} for the branching fraction of B{sup 0} {yields} invisible and 1.7 x 10{sup -5} for the branching fraction of B{sup 0} {yields} invisible + {gamma}.
Lees, J.P.; Poireau, V.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Palano, A.; /Bari U. /INFN, Bari; Eigen, G.; Stugu, B.; /Bergen U.; Brown, David Nathan; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; /LBL, Berkeley /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum; Asgeirsson, D.J.; Hearty, C.; Mattison, T.S.; McKenna, J.A.; So, R.Y.; /British Columbia U.; Khan, A.; /Brunel U.; Blinov, V.E.; /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /Ferrara U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Indian Inst. Tech., Guwahati /Harvard U. /Harvey Mudd Coll. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U., Comp. Sci. Dept. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /Milan U. /INFN, Milan /Mississippi U. /Montreal U. /Naples U. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U.; /more authors.; ,
Study of High-multiplicity 3-prong and 5-prong Tau Decays at BaBar
We present measurements of the branching fractions of 3-prong and 5-prong {tau} decay modes using a sample of 430 million {tau} lepton pairs, corresponding to an integrated luminosity of 468 fb{sup -1}, collected with the BABAR detector at the PEP-II asymmetric energy e{sup +}e{sup -} storage rings. The {tau}{sup -} {yields} (3{pi}){sup -} {eta}{nu}{sub {tau}}, {tau}{sup -} {yields} (3{pi}){sup -} {yields} {omega}{nu}{sub {tau}} and {tau}{sup -} {yields} {pi}{sup -} f{sub 1}(1285){nu}{sub {tau}} branching fractions are presented as well as a new limit on the branching fraction of the isospin-forbidden, second-class current {tau}{sup -} {yields} {pi}{sup -} {eta}{prime}(958){nu}{sub {tau}} decay. We find no evidence for charged kaons in these decay modes and place the first upper limits on their branching fractions.
Lees, J.P
B and D meson decay constants from 2+1 flavor improved staggered simulations
We give an update on simulation results for the decay constants f{sub B}; f{sub B{sub s}}, f{sub D} and f{sub D{sub s}}. These decay constants are important for precision tests of the standard model, in particular entering as inputs to the global CKM unitarity triangle fit. The results presented here make use of the MILC (2+1)-flavor asqtad ensembles, with heavy quarks incorporated using the clover action with the Fermilab method. Partially quenched, staggered chiral perturbation theory is used to extract the decay constants at the physical point. In addition, we give error projections for a new analysis in progress, based on an extended data set.
Neil, E.T.; Bailey, Jon A.; Bazavov, A.; Bernard, C.; Bouchard, C.M.; DeTar, C.; Di Pierro, M.; El-Khadra, A.X.; Evans, R.T.; Freeland, E.; Gamiz, E.
Analysis of the D+ --> K- pi+ e+ nu_e decay channel
Using 347.5 fb{sup -1} of data recorded by the BABAR detector at the PEP-II electron-positron collider, 244 x 10{sup 3} signal events for the D{sup +} {yields} K{sup -}{pi}{sup +}e{sup +}{nu}{sub e} decay channel are analyzed. This decay mode is dominated by the {bar K}*(892){sup 0} contribution. We determine the {bar K}*(892){sup 0} parameters: m{sub K*(892){sup 0}} = (895.4{+-}0.2{+-}0.2) MeV/c{sup 2}, {Lambda}{sub K*(892){sup 0}}{sup 0} = (46.5{+-}0.3{+-}0.2) MeV/c{sup 2} and the Blatt-Weisskopf parameter r{sub BW} = 2.1{+-}0.5{+-}0.5 (GeV/c){sup -1} where the first uncertainty comes from statistics and the second from systematic uncertainties. We also measure the parameters defining the corresponding hadronic form factors at q{sup 2} = 0 (r{sub V} = V(0)/A{sub 1}(0) = 1.463{+-}0.017{+-}0.031, r{sup 2} = A{sub 2}(0)/A{sub 1}(0) = 0.801{+-}0.020{+-}0.020) and the value of the axial-vector pole mass parameterizing the q{sup 2} variation of A{sub 1} and A{sub 2}: m{sub A} = (2.63{+-}0.10{+-}0.13) GeV/c{sup 2}. The S-wave fraction is equal to (5.79{+-}0.16{+-}0.15)%. Other signal components correspond to fractions below 1%. Using the D{sup +} {yields} K{sup -}{pi}{sup +}{pi}{sup +} channel as a normalization, we measure the D{sup +} semileptonic branching fraction: {Beta}(D{sup +} {yields} K{sup -}{pi}{sup +}e{sup +}{nu}{sub e}) = (4.00 {+-} 0.03 {+-} 0.04 {+-} 0.09) x 10{sup -2} where the third uncertainty comes from external inputs. We then obtain the value of the hadronic form factor A{sub 1} at q{sup 2} = 0: A{sub 1}(0) = 0.6200 {+-} 0.0056 {+-} 0.0065 {+-} 0.0071. Fixing the P-wave parameters we measure the phase of the S-wave for several values of the K{pi} mass. These results confirm those obtained with K{pi} production at small momentum transfer in fixed target experiments.
del Amo Sanchez, P.; Lees, J.P.; Poireau, V.; Prencipe, E.; Tisserand, V.; /Annecy, LAPP; Garra Tico, J.; Grauges, E.; /Barcelona U., ECM; Martinelli, M.; /INFN, Bari /Bari U.; Milanes, D.A.; /Bari U.; Palano, A.; Pappagallo, M.; /INFN, Bari /Bari U.; Eigen, G.; Stugu, B.; Sun, L.; /Bergen U.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /UC, Berkeley; Koch, H.; Schroeder, T.; /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UC, Riverside /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /INFN, Ferrara /INFN, Ferrara /Ferrara U. /INFN, Ferrara /Frascati /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /INFN, Genoa /INFN, Genoa /Genoa U. /Indian Inst. Tech., Guwahati /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa State U. /Iowa State U. /Johns Hopkins U. /Paris U., VI-VII /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Royal Holloway, U. of London /Louisville U. /Mainz U., Inst. Kernphys. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Milan U. /INFN, Milan /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /INFN, Padua /INFN, Padua /Padua U. /Paris U., VI-VII /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /INFN, Pisa /Pisa, Scuola Normale Superiore /INFN, Pisa /Pisa U. /INFN, Pisa /Princeton U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /INFN, Rome /INFN, Rome /Rome U. /Rostock U. /Rutherford /DAPNIA, Saclay /SLAC /South Carolina U. /Southern Methodist U. /Stanford U., Phys. Dept. /SUNY, Albany /Tel Aviv U. /Tennessee U. /Texas Nuclear Corp., Austin /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U. /Victoria U. /Warwick U. /Stanford U., Phys. Dept.
Rapid Orbital Decay in the 12.75-minute WD+WD Binary J0651+2844
We report the detection of orbital decay in the 12.75-min, detached binary white dwarf (WD) SDSS J065133.338+284423.37 (hereafter J0651). Our photometric observations over a 13-month baseline constrain the orbital period to 765.206543(55) s and indicate the orbit is decreasing as a rate of (-9.8 +/- 2.8) x 10^(-12) s/s (or -0.31 +/- 0.09 ms/yr). We revise the system parameters based on our new photometric and spectroscopic observations: J0651 contains two WDs with M1 = 0.26 +/- 0.04 Msun and M2 = 0.50 +/- 0.04 Msun. General relativity predicts orbital decay due to gravitational wave radiation of (-8.2 +/- 1.7) x 10^(-12) s/s (or -0.26 +/- 0.05 ms/yr). Our observed rate of orbital decay is consistent with this expectation. J0651 is currently the second-loudest gravitational wave source known in the milli-Hertz range and the loudest non-interacting binary, which makes it an excellent verification source for future missions aimed at directly detecting gravitational waves. Our work establishes the feasibility of ...
Hermes, J J; Brown, Warren R; Winget, D E; Prieto, Carlos Allende; Gianninas, A; Mukadam, Anjum S; Cabrera-Lavers, Antonio; Kenyon, Scott J
Pareto optimal structures producing resonances of minimal decay under $L^1$-type constraints
Optimization of resonances associated with 1-D wave equations in inhomogeneous media is studied under the constraint $\\| B \\|_1 rate $| Im \\omega |$. Such resonances are said to be of minimal decay and form a Pareto frontier. We show that corresponding optimal measures consist of finite number of point masses, and that this result yields non-existence of optimizers for the problem over the set of absolutely continuous measures $B(x) dx$. Then we derive restrictions on optimal point masses and their positions. These restrictions are strong enough to calculate optimal $d M$ if the optimal resonance $ \\omega $, the first point mass $m_1$, and one more geometric parameter are known. This reduces the original infinitely-dimensional problem to optimization over four real parameters. For small frequencies, we explicitly find the Pareto set and the corresponding optimal measures $d M$. The technique of the paper is based on the two-parameter perturbation method and the notion of local boundary point. The latter is introduced as a generalization of local extrema to vector optimization problems.
Illya M. Karabash
The formation and decay of superheavy nuclei produced in $^{48}Ca$-induced reactions
The formation of superheavy nuclei in $^{48}Ca+^{232}Th$, $^{238}U$, $^{242,244}Pu$ and $^{248}Cm$ reactions and their subsequent decay are studied within the quantum mechanical fragmentation theory (QMFT) and the QMFT based preformed cluster-decay model (PCM) of Gupta and collaborators. According to QMFT, all these $^{48}Ca$-induced reactions are cold fusion reactions with relative excitation energies larger than for the $Pb$-induced cold fusion reactions and smaller than for the lighter beam i.e. $Mg$, $Si$ or $S$-induced hot fusion reactions. The same reactions were first suggested by Gupta et al. in 1977 on the basis of QMFT, and this study re-establishes the same result. In fact, for such heavy isotopes of Z=110 to 116, $^{50}Ca$ is shown to be a better beam for cold fusion, but $^{50}Ca$ is a radioactive nucleus. The $\\alpha$-decay half-lives of these nuclei after 3n and/ or 4n evaporations, i.e. of the evaporation residues of these compound systems, calculated on PCM compare reasonably well with experiments published by Dubna group and another recent calculation. As expected for such rare decays, PCM calculations show that the $\\alpha$-preformation factors are small, $\\sim 10^{-8}$ to $10^{-10}$. The possible competition of $\\alpha$-decays with heavy cluster emissions from these superheavy nuclei is also probed from the point of view of searching for new nuclear structure information and possible future experiments with such exotic nuclei. The decay half-lives for some clusters are in fact shown to be lower than the limits of experiments for nuclei with enough available atoms.
Sushil Kumar; M. Balasubramaniam; Raj K. Gupta; G. Munzenberg; W. Scheid
Search For the Rare Decay K(L) ---> pi0 pi0 gamma
This thesis describes a search for the rare decay K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{gamma} using data from the KTeV experiment, using the topology K{sub L} {yields} {pi}{sup 0}{pi}{sub D}{sup 0}{gamma} (where {pi}{sub D}{sup 0} {yields} {gamma}e{sup +}e{sup -}). Due to Bose statistics and the real nature of the photon, the K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{gamma} decay can proceed at lowest order only by the Cp conserving direct emission of an E2 photon. The decay vanishes to O(p{sup 4}) in chiral perturbation theory and is a probe of the theory to the sixth order. The primary background to this decay consists of K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sub D}{sup 0} events with one lost photon. The upper limit for the decay K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{gamma} presented in this thesis is 2.32 x 10{sup -7} at the 90% confidence level. This upper limit was derived from both 1997 and 1999 data, using a blind analysis. The upper limit was derived from a Feldman-Cousins method, based on a weighted total of 0.53 data events in the signal region with an expected K{sub L} {yields} {pi}{sup 0}{pi}{sup 0}{pi}{sub D}{sup 0} background of 0.37 {+-} 0.28 events. The previous upper limit for this decay was 5.6 x 10{sup -6} at the 90% confidence level.
Smith, David Edward; /Virginia U.
Investigation of novel decay B _____ ____(2S)____K at BaBar
We investigate the undocumented B meson decay, B{sup +} {yields} {Psi}(2S){omega}K{sup +}. The data were collected with the BaBar detector at the SLAC PEP-II asymmetric-energy e{sup +}e{sup -} collier operating at the {gamma}(4S) resonance, a center-of-mass energy of 10.58 GeV/c{sup 2}. The {gamma}(4S) resonance primarily decays to pairs of B-mesons. The BaBar collaboration at the PEP-II ring was located at the SLAC National Accelerator Laboratory and was designed to study the collisions of positrons and electrons. The e{sup -}e{sup +} pairs collide at asymmetric energies, resulting in a center of mass which is traveling at relativistic speeds. The resulting time dilation allows the decaying particles to travel large distances through the detector before undergoing their rapid decays, a process that occurs in the in the center of mass frame over extremely small distances. As they travel through silicon vertex trackers, a drift chamber, a Cerenkov radiation detector and finally an electromagnetic calorimeter, we measure the charge, energy, momentum, and particle identification in order to reconstruct the decays that have occurred. While all well understood mesons currently fall into the qq model, the quark model has no a priori exclusion of higher configuration states such as qqqq which has led experimentalists and theorists alike to seek evidence supporting the existence of such states. Currently, there are hundreds of known decay modes of the B mesons cataloged by the Particle Data Group, but collectively they only account for approximately 60% of the B branching fraction and it is possible that many more exist.
Schalch, Jacob; /Oberlin Coll. /SLAC
Combining and comparing neutrinoless double beta decay experiments using different nuclei
We perform a global fit of the most relevant neutrinoless double beta decay experiments within the standard model with massive Majorana neutrinos. Using Bayesian inference makes it possible to take into account the theoretical uncertainties on the nuclear matrix elements in a fully consistent way. First, we analyze the data used to claim the observation of neutrinoless double beta decay in Ge-76, and find strong evidence (according to Jeffrey's scale) for a peak in the spectrum and moderate evidence for that the peak is actually close to the energy expected for the neutrinoless decay. We also find a significantly larger statistical error than the original analysis, which we include in the comparison with other data. Then, we statistically test the consistency between this claim with that of recent measurements using Xe-136. We find that the two data sets are about 40 to 80 times more probable under the assumption that they are inconsistent, depending on the nuclear matrix element uncertainties and the prior on the smallest neutrino mass. Hence, there is moderate to strong evidence of incompatibility, and for equal prior probabilities the posterior probability of compatibility is between 1.3% and 2.5%. If one, despite such evidence for incompatibility, combines the two data sets, we find that the total evidence of neutrinoless double beta decay is negligible. If one ignores the claim, there is weak evidence against the existence of the decay. We also perform approximate frequentist tests of compatibility for fixed ratios of the nuclear matrix elements, as well as of the no signal hypothesis. Generalization to other sets of experiments as well as other mechanisms mediating the decay is possible.
Johannes Bergstrom
{psi}(2S) Hadronic Decays to Vector-Tensor Final States
The decays of the {psi}(2S) into vector plus tensor meson final states have been studied for the first time using the BES detector. We determine upper limits on branching fractions for {psi}(2S) decays into {omega}f{sub 2} , {rho}a{sub 2} , K{sup {asterisk}0}{ovr K}{sup *0}{sub 2}+c.c. , and {phi}f{sup {prime}}{sub 2}(1525) that are, in each case, significantly smaller than the corresponding branching fractions for the J/{psi} meson, scaled according to the expectations of perturbative QCD. {copyright} {ital 1998} {ital The American Physical Society }
Bai, J.Z.; Bian, J.G.; Chai, Z.W.; Chen, G.P.; Chen, J.C.; Chen, Y.; Chen, Y.B.; Chen, Y.Q.; Cheng, B.S.; Cui, X.Z.; Ding, H.L.; Ding, L.Y.; Dong, L.Y.; Du, Z.Z.; Feng, S.; Gao, C.S.; Gao, M.L.; Gao, S.Q.; Gu, J.H.; Gu, S.D.; Gu, W.X.; Gu, Y.F.; Guo, Y.N.; Han, S.W.; Han, Y.; He, J.; He, J.T.; Hu, G.Y.; Hu, H.M.; Hu, J.L.; Hu, Q.H.; Hu, T.; Hu, X.Q.; Huang, J.D.; Huang, Y.Z.; Jiang, C.H.; Jin, Y.; Ke, Z.J.; Lai, Y.F.; Lang, P.F.; Li, C.G.; Li, D.; Li, H.B.; Li, J.; Li, P.Q.; Li, R.B.; Li, W.; Li, W.D.; Li, W.G.; Li, X.H.; Li, X.N.; Liu, H.M.; Liu, J.; Liu, J.H.; Liu, R.G.; Liu, Y.; Lu, F.; Lu, J.G.; Lu, J.Y.; Lu, L.C.; Luo, C.H.; Ma, A.M.; Ma, E.C.; Ma, J.M.; Mao, H.S.; Mao, Z.P.; Meng, X.C.; Nie, J.; Qi, N.D.; Qi, X.R.; Qiu, J.F.; Qu, Y.H.; Que, Y.K.; Rong, G.; Shao, Y.Y.; Shen, B.W.; Shen, D.L.; Shen, H.; Shen, X.Y.; Sheng, H.Y.; Shi, H.Z.; Song, X.F.; Sun, F.; Sun, H.S.; Tang, S.Q.; Tong, G.L.; Wang, F.; Wang, L.S.; Wang, L.Z.; Wang, M.; Wang, M.; Wang, P.; Wang, P.L.; Wang, S.M.; Wang, T.J.; Wang, Y.Y.; Wei, C.L.; Wu, Y.G.; Xi, D.M.; Xia, X.M.; Xie, P.P.; Xie, Y.; Xie, Y.H.; Xiong, W.J.; Xu, C.C.; Xu, G.F.; Xue, S.T.; Yan, J.; Yan, W.G.; Yang, C.M.; Yang, C.Y.; Yang, J.; Yang, X.F.; Ye, M.H.; Yi, K.; Yu, C.S.; Yu, C.X.; Yu, Z.Q.; Yu, Z.T.; Yuan, C.Z.; Yuan, Y.; Zhang, B.Y.; Zhang, C.C.; Zhang, D.H.; Zhang, D.; Zhang, H.L.; Zhang, J.; Zhang, J.L.; Zhang, J.W.; Zhang, L.S.; Zhang, Q.J.; Zhang, S.Q.; Zhang, Y.; Zhang, Y.Y.; Zhao, D.X.; Zhao, H.W.; Zhao, J.W.; Zhao, M.; Zhao, W.R.; Zhao, Z.G.; Zheng, J.P.; Zheng, L.S.; Zheng, Z.P.; Zhou, G.P.; Zhou, H.S.; Zhou, L.; Zhu, Q.M.; Zhu, Y.C.; Zhu, Y.S.; Zhuang, B.A. [Institute of High Energy Physics, Beijing 100039, People`s Republic of (China)] [Institute of High Energy Physics, Beijing 100039, People`s Republic of (China); Hitlin, D.G.; Kelsey, M.H.; Oyang, J.; Panetta, J.; Porter, F.; Weaver, M. [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States); Chen, J.; Malchow, R.; Toki, W.; Yang, W. [Colorado State University, Colorado 80523 (United States)] [Colorado State University, Colorado 80523 (United States)
Photon decay in strong magnetic field in heavy-ion collisions
We calculate the photon pair production rate in strong magnetic field created in off-central heavy-ion collisions. Photon decay leads to depletion of the photon yield by a few percent at RHIC and by as much as 20% at the LHC. It also generates a substantial azimuthal asymmetry ("elliptic flow") of the final photon distribution. We estimate v_2~2% at RHIC and v_2~14% at LHC. Photon decay measurements is an important tool for studying the magnetic fields in early stages of heavy-ion collisions.
Tuchin, Kirill
Exotic Higgs Decay h to 2a at the International Linear Collider: a Snowmass White Paper
A Higgs factory like the International Linear Collider (ILC) can play a significant role in searching for exotic decays of Higgs bosons. As an illustration, we investigate the ILC sensitivity for the decay topology $h\\to a_1 a_1 \\to \\tau\\bar \\tau\\tau \\bar \\tau$ in the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM). Here $h$ can be either Standard-Model-like or non-standard, and $a_{1}$ is the lightest CP-odd Higgs boson. We also compare results to expectations for this channel at the LHC.
Tao Liu; C. T. Potter
Radiative and semileptonic B meson decay spectra: Sudakov resummation beyond logarithmic accuracy and the pole mass.
function 31 1. Introduction Inclusive B�meson decay processes, such as the semi-leptonic process B� ?? Xul??�l and the rare B� ?? Xs? process, attract much attention in the recent years [1�27]. This is primarily because of the availability of increasingly... ) guarantee infrared safety. Consequently, the b�quark � 1 � decay spectra are calculable in perturbative QCD. On the other hand, the fact that the b quark is part of a bound state has a significant impact on the spectra. It has been understood long ago...
Gardi, Einan
Negative parity baryon decays in the 1/N{sub c} expansion
The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6) are analyzed in the framework of the 1/N{sub c} expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/N{sub c} and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are obtained.
Jayalath, C. [Department of Physics, Hampton University, Hampton, Virginia 23668 (United States); Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Department of Physics, Peradeniya University, Peradeniya 20400 (Sri Lanka); Goity, J. L. [Department of Physics, Hampton University, Hampton, Virginia 23668 (United States); Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States); Gonzalez de Urreta, E. [Department of Theoretical Physics, Comision Nacional de Energia Atomica, 1429 Buenos Aires (Argentina); CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina); Scoccola, N. N. [Department of Theoretical Physics, Comision Nacional de Energia Atomica, 1429 Buenos Aires (Argentina); CONICET, Rivadavia 1917, 1033 Buenos Aires (Argentina); Universidad Favaloro, Solis 453, 1078 Buenos Aires (Argentina)
Importance of electronic relaxation for inter-coulombic decay in aqueous systems
Inspired by recent photoelectron spectroscopy (PES) experiments on hydroxide solutions, we have examined the conditions necessary for enhanced (and, in the case of solutions, detectable) intercoulombic decay (ICD)--Auger emission from an atomic site other than that originally excited. We present general guidelines, based on energetic and spatial overlap of molecular orbitals, for this enhancement of ICDbased energy transfer in solutions. These guidelines indicate that this decay process should be exhibited by broad classes of biomolecules and suggest a design criterion for targeted radiooncology protocols. Our findings show that PES cannot resolve the current hydroxide coordination controversy.
Schwartz, Craig P.; Fatehi, Shervin; Saykally, Richard J.; Prendergast, David
Higgs boson decays to $??$ and $Z ?$ in models with Higgs extensions
The decays of a Higgs boson to the $\\gamma\\gamma$ and $Z\\gamma$ final states are purely quantum mechanical phenomena that are closely related to each other. We study the effects of an extended Higgs sector on the decay rates of the two modes. We propose that a simultaneous determination of them and the $ZZ$ mode is a useful way to see whether the Higgs boson recently observed by the LHC experiments is of the standard model type or could be a member of a larger Higgs sector.
Cheng-Wei Chiang; Kei Yagyu
Diphoton Decay Excess and 125 GeV Higgs Boson in Gauge-Higgs Unification
In the context of gauge-Higgs unification scenario in a 5-dimensional flat spacetime, we investigate Higgs boson production via gluon fusion and its diphoton decay mode at the LHC. We show that the signal strength of the Higgs diphoton decay mode observed at ATLAS and CMS, which is considerably larger than the Standard Model expectation, can be explained by a simple gauge-Higgs unification model with color-singlet bulk fermions to which a half-periodic boundary condition is assigned. The bulk fermions also play a crucial role in reproducing the observed Higgs boson mass around 125 GeV.
Nobuhito Maru; Nobuchika Okada
How to measure the spreading width for decay of superdeformed nuclei
A new expression for the branching ratio for the decay via the E1 process in the normal-deformed band of superdeformed nuclei is given within a simple two-level model. Using this expression, the spreading or tunneling width Gamma^downarrow for superdeformed decay can be expressed entirely in terms of experimentally known quantities. We show how to determine the tunneling matrix element V from the measured value of Gamma^downarrow and a statistical model of the energy levels. The accuracy of the two-level approximation is verified by considering the effects of the other normal-deformed states.
D. M. Cardamone; C. A. Stafford; B. R. Barrett
Laser-induced synthesis and decay of Tritium under exposure of solid targets in heavy water
The processes of laser-assisted synthesis of Tritium nuclei and their laser-induced decay in cold plasma in the vicinity of solid targets (Au, Ti, Se, etc.) immersed into heavy water are experimentally realized at peak laser intensity of 10E10-10E13 Watts per square centimeter. Initial stages of Tritium synthesis and their laser-induced beta-decay are interpreted on the basis of non-elastic interaction of plasma electrons having kinetic energy of 5-10 eV with nuclei of Deuterium and Tritium, respectively.
E. V. Barmina; P. G. Kuzmin; S. F. Timashev; G. A. Shafeev
CEBAF-TH-93-18 Quasi-Two-Body Decays of Nonstrange Baryons
(1440)?, and ?2 (1600)?, in a relativized pair-creation ( 3P0) model which has been developed in a previous study of the N? decays of the same baryon states. As it is our goal to provide a guide for the possible discovery of new baryon states at CEBAF and elsewhere, we examine the decays of resonances which have already been seen in the partial-wave analyses, along with those of states which are predicted by the quark model but which remain undiscovered. The level of agreement between our calculation and the available widths from the partial-wave analyses is encouraging. Typeset Using REVTEX
Simon Capstick; Winston Roberts
Optimization of the Transport Shield for Neutrinoless Double Beta-decay Enriched Germanium
This document presents results of an investigation of the material and geometry choice for the transport shield of germanium, the active detector material used in 76Ge neutrinoless double beta decay searches. The objective of this work is to select the optimal material and geometry to minimize cosmogenic production of radioactive isotopes in the germanium material. The design of such a shield is based on the calculation of the cosmogenic production rate of isotopes that are known to cause interfering backgrounds in 76Ge neutrinoless double beta decay searches.
Aguayo Navarrete, Estanislao; Kouzes, Richard T.; Orrell, John L.; Reid, Douglas J.; Fast, James E.
The Case for a Solar Influence on Certain Nuclear Decay Rates
Power-spectrum analyses of the decay rates of certain nuclides reveal (at very high confidence levels) an annual oscillation and periodicities that may be attributed to solar rotation and to solar r-mode oscillations. A comparison of spectrograms (time-frequency displays) formed from decay data and from solar neutrino data reveals a common periodicity with frequency 12.5 year-1, which is indicative of the solar radiative zone. We propose that the neutrino flux is modulated by the solar magnetic field (via Resonant Spin Flavor Precession) in that region, and we estimate the force and the torque that could be exerted on a nuclide by the solar neutrino flux.
Peter Sturrock; Ephraim Fischbach; Daniel Javorsek II; Jere Jenkins; Robert Lee
The partial decay widths of lowest lying negative parity baryons belonging to the 70-plet of SU(6)are analyzed in the framework of the 1/N{sub c} expansion. The channels considered are those with single pseudoscalar meson emission. The analysis is carried out to sub-leading order in 1/Nc and to first order in SU(3) symmetry breaking. Conclusions about the magnitude of SU(3) breaking effects along with predictions for some unknown or poorly determined partial decay widths of known resonances are given.
Chandana Jayalath,Jose Goity,Emiliano Gonzalez de Urreta,Norberto Scoccola
Angular Distribution of Charming B -> V V Decays and Time Evolution Effects
Angular distributions of a B meson decaying into two vector mesons are discussed with emphasis on time evolution effects on the complete set of amplitude bilinears. Time integrated quantities are suggested to observe substantial CP violation in decays with charm quarks in the final state particles. Relations among the nine observables at $t=0$ are found to be useful for a consistency check of experimentally extracted quantities. Numerical estimates of the nine observables are made using form factor models and the assumption of the factorization hypothesis. Branching ratio asymmetries for B_u^+ -> D^{*+} \\bar D^{*0} and B_d -> D^{*+} D^{*-} can be as large as -3% and -4%, respectively.
Angular Distribution of Charming $B \\to V V$ Decays and Time Evolution Effects
Angular distributions of a B meson decaying into two vector mesons arediscussed with emphasis on time evolution effects on the complete set ofamplitude bilinears. Time integrated quantities are suggested to observesubstantial CP violation in decays with charm quarks in the final stateparticles. Relations among the nine observables at $t=0$ are found to be usefulfor a consistency check of experimentally extracted quantities. Numericalestimates of the nine observables are made using form factor models and theassumption of the factorization hypothesis. Branching ratio asymmetries forB_u^+ -> D^{*+} \\bar D^{*0} and B_d -> D^{*+} D^{*-} can be as large as -3and-4, respectively.